JP5110484B2 - Rare earth complexes and their use - Google Patents

Description

  The present invention relates to a rare earth complex and use thereof, and more particularly to a rare earth complex having photochromic properties and use thereof.

  A photochromic material is a material containing a molecule or molecular assembly that reversibly generates two isomers having different states by the action of light. The two isomers differ in optical properties such as light absorption coefficient, refractive index, optical rotation, and dielectric constant. In addition, isomerization between the two isomers occurs reversibly by a photochemical reaction (also referred to as a photochromic reaction) with light of a specific wavelength. That is, a photochromic material is a substance that can be reversibly changed to a molecular structure with different optical properties by irradiation with specific light. Therefore, photochromic materials are applied to optical memories, optical switches, dimming lenses, radiation dosimeters, etc. by utilizing the difference in optical properties between the two isomers and the reversible variability between the two isomers. Technology development is in progress.

  For example, when a photochromic material is used as an optical memory element, information can be recorded using light of a specific wavelength as recording light. The recorded information can be read (reproduced) by absorbing light. Moreover, the recorded information can be erased by irradiating light of a specific wavelength.

  When a photochromic material is used as an optical memory element, reading of information recorded in the optical memory element is usually performed using a difference in light absorption as described above. However, since the photochromic reaction has no threshold value, the recorded information is destroyed when the information is read out by the measurement light for measuring the light absorption. Therefore, it is difficult to read information many times. Therefore, in an optical memory element using a photochromic material, reading information in a non-destructive manner is one of the problems, and various studies have been conducted on this. For example, a method of reading out information using a difference in another optical characteristic such as a refractive index, a method of introducing a hydrogen bond into a photochromic molecule, a method of electrically recording information, and the like have been proposed.

  By the way, it is known that some rare earth ions emit light in a wide wavelength range from ultraviolet to infrared. These luminescences are based on electronic transitions derived from f-orbitals that are not easily affected by external fields such as ligand fields. Therefore, the wavelength width of the emission band is very narrow compared to organic phosphors and the like, and in principle, the color purity is extremely useful. In addition, organic phosphors are inferior in stability to heat, light, and excitation. Moreover, since rare earth ions are non-toxic, they are easy to use industrially. Thus, since rare earth ions have excellent characteristics, rare earth complexes in which various ligands are coordinated with rare earth ions are used in various applications. Specifically, it is used for various applications such as luminescent ink and organic electroluminescence element.

In addition, in order to make it possible to apply rare earth ions having such excellent characteristics to a wider range of fields, various studies have been conducted on rare earth ions and rare earth complexes. For example, recently, the present inventors have clarified that the emission intensity of rare earth ions in a rare earth complex varies depending on the type of ligand coordinated to the rare earth complex (see Non-Patent Document 1). ). Non-Patent Document 1 discloses that when the ligand coordinated to Eu (III) is variously changed, the emission characteristics of the complex change depending on the structure of the ligand.
Hasegawa Y. et al., J. Phys. Chem. A 107, 1697-1702 (2003).

  As described above, the photochromic material is expected to be applied to various uses such as an optical memory and an optical switch. However, when a conventional photochromic material is used as an optical memory, the information recorded in the optical memory is erased at that time when the light for reading the information recorded in the optical memory is irradiated. There is a problem that it cannot be used.

  In addition, the information recorded in the optical memory is read out by using different optical characteristics such as the refractive index instead of the absorption characteristics, hydrogen bonds are introduced into the photochromic material, and information is electrically recorded. However, this method is not sufficient for practical use.

  The present invention has been made in view of the above problems, and an object thereof is to provide a new photochromic material that can be applied to a nonvolatile memory and the like, and use thereof.

  As a result of intensive studies in view of the above problems, the present inventors have found that the rare earth ions are obtained by utilizing the photochromic reactivity of the photochromic ligand according to the rare earth complex in which the rare earth ions are coordinated with the photochromic ligand. The inventors have uniquely found that the light emission characteristics of the light can be controlled reversibly, and have completed the present invention. That is, the present invention includes the following inventions.

  (1) A rare earth complex having a structure in which a photochromic ligand is coordinated to a rare earth ion.

  (2) The photochromic ligand is represented by the following general formula (1)

Wherein R ₁ and R ₈ are each independently an alkyl group, alkoxyl group, halogen atom, trifluoromethyl group, fluorine-substituted alkyl group, cyano group, hydroxyl group, carboxyl group, sulfonyl group, aryl group or substituted. R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , and R ₇ are each independently a hydrogen atom, alkyl group, alkoxyl group, halogen atom, trifluoromethyl group, fluorine-substituted alkyl Group, cyano group, hydroxyl group, carboxyl group, sulfonyl group, aryl group or substituted aryl group, or R ₂ and R ₃ , R ₃ and R ₄ , R ₄ and R ₅ , or R ₆ and R carbocyclic ring linked to each other and _7, heterocycle, substituted carbocyclic, or forms a substituted _{heterocycle, R 2, R 3, R} 4, _{5, R 6,} and at least one of _{R 7,} include a nitrogen atom, an oxygen atom, a sulfur atom or P = O structure)
The rare earth complex according to (1), wherein the rare earth complex is represented by the formula:

  (3) The photochromic ligand is represented by the following general formula (2)

Wherein R ₁ and R ₆ are each independently an alkyl group, alkoxyl group, halogen atom, trifluoromethyl group, fluorine-substituted alkyl group, cyano group, hydroxyl group, carboxyl group, sulfonyl group, aryl group or substituted. R ₂ and R ₅ are each independently a hydrogen atom, alkyl group, alkoxyl group, halogen atom, trifluoromethyl group, fluorine-substituted alkyl group, cyano group, hydroxyl group, carboxyl group, sulfonyl group, An aryl group or a substituted aryl group, wherein R ₃ and R ₄ are each independently a hydrogen atom, alkyl group, alkoxyl group, halogen atom, trifluoromethyl group, fluorine-substituted alkyl group, cyano group, hydroxyl group, carboxyl Group, sulfonyl group, aryl group or substituted aryl group There, or a carbon ring linking R ₃ and R ₄ together, heterocycle, substituted carbocyclic, or forms a substituted heterocycle, X and Y are each independently CH , A nitrogen atom, an oxygen atom, or a sulfur atom, and at least one of R ₂ , R ₃ , R ₄ , R ₅ , X, and Y includes a nitrogen atom, an oxygen atom, or a sulfur atom)
The rare earth complex according to (1), wherein the rare earth complex is represented by the formula:

  (4) In the general formula (2), at least one of X and Y is a nitrogen atom, an oxygen atom, or a sulfur atom.

  (5) The photochromic ligand is represented by the following general formula group (3)

(Wherein R ₁ , R ₆ , R ₇ , R ₈ , R ₉ and R ₁₀ are each independently an alkyl group, an alkoxyl group, a halogen atom, a trifluoromethyl group, a fluorine-substituted alkyl group, a cyano group, A hydroxyl group, a carboxyl group, a sulfonyl group, an aryl group or a substituted aryl group, and R ₂ and R ₅ are each independently a hydrogen atom, an alkyl group, an alkoxyl group, a halogen atom, a trifluoromethyl group, or a fluorine-substituted alkyl. Group, cyano group, hydroxyl group, carboxyl group, sulfonyl group, aryl group or substituted aryl group, R ₃ and R ₄ are each independently a hydrogen atom, an alkyl group, an alkoxyl group, a halogen atom, trifluoromethyl. Group, fluorine-substituted alkyl group, cyano group, hydroxyl group, carboxyl group, sulfonyl group, Whether it is Le group or substituted aryl group, or, to form a carbon ring linked R ₃ and R ₄ together, heterocycle, substituted carbocyclic, or a substituted heterocyclic)
The rare earth complex according to (1), wherein the rare earth complex is a ligand represented by any one of the following:

  (6) The photochromic ligand is represented by the following general formula (4):

Wherein R ₁ and R ₅ are each independently an alkyl group, alkoxyl group, halogen atom, trifluoromethyl group, fluorine-substituted alkyl group, cyano group, hydroxyl group, carboxyl group, sulfonyl group, aryl group or substituted. R ₂ , R ₃ , and R ₄ are each independently a hydrogen atom, alkyl group, alkoxyl group, halogen atom, trifluoromethyl group, fluorine-substituted alkyl group, cyano group, hydroxyl group, carboxyl group A sulfonyl group, an aryl group or a substituted aryl group)
The rare earth complex according to (1), wherein the rare earth complex is represented by the formula:

  (7) The following general formula group (5)

(Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , R ₉ , R ₁₀ , R ₁₁ , and R ₁₂ are each independently an alkyl group, alkoxyl Group, halogen atom, trifluoromethyl group, fluorine-substituted alkyl group, cyano group, hydroxyl group, carboxyl group, sulfonyl group, aryl group or substituted aryl group, or linked to each other between adjacent substituents To form a carbocycle, heterocycle, substituted carbocycle, or substituted heterocycle)
The rare earth complex according to (1), wherein the ligand represented by any one of the above is further coordinated to the rare earth ion.

  (8) The following general formula (6)

Wherein R ₁ and R ₅ are each independently an alkyl group, alkoxyl group, halogen atom, trifluoromethyl group, fluorine-substituted alkyl group, cyano group, hydroxyl group, carboxyl group, sulfonyl group, aryl group or substituted. R ₂ , R ₃ , and R ₄ are each independently a hydrogen atom, alkyl group, alkoxyl group, halogen atom, trifluoromethyl group, fluorine-substituted alkyl group, cyano group, hydroxyl group, carboxyl group , A sulfonyl group, an aryl group or a substituted aryl group, wherein R ₅ and R ₆ are each independently an alkyl group having 1 to 8 carbon atoms, a fluorine-substituted alkyl group having 1 to 8 carbon atoms, or a phenyl group. Ln is a rare earth ion, n is an integer of 1 to 5, m is an integer of 0 to 4, and the sum of n and m 5 is less than or equal to.)
Rare earth complex represented by

  (9) The rare earth complex according to (1) or (8), wherein the rare earth ion is a trivalent lanthanoid ion.

(10) The rare earth ion is Ce ³⁺ , Nd ³⁺ , Sm ³⁺ , Eu ³⁺ , Tb ³⁺ , Dy ³⁺ , Er ³⁺ , Pr ³⁺ , Tm ³⁺ , or Yb ³⁺ (1) or ( The rare earth complex as described in 8).

  (11) A composition comprising the rare earth complex according to any one of (1) to (10) and a medium.

(12) a recording step of recording information on the photochromic ligand by irradiating light of wavelength λ _{1 to} the rare earth complex having a structure in which the photochromic ligand is coordinated to the rare earth ion; and the rare earth complex. irradiating light of wavelength lambda _3, the information received emission from the rare earth complexes, the emission intensity of the light emitting determined, based on the emission intensity of the measured light-emitting, recorded on the photochromic ligand And a reproducing step of reproducing the information.

(13) by irradiating the light of the rare earth complex to the wavelength lambda _2, the information recording and reproducing according to the above, further comprising an erasing step of erasing information recorded on the photochromic ligand (12) Method.

(14) For a rare earth complex having a structure in which a photochromic ligand is coordinated to a rare earth ion, a first irradiation step of irradiating light with a wavelength λ ₁ , and a rare earth complex after the first irradiation step, the irradiated with light of wavelength lambda _3, receives the light emission from the rare earth complex is irradiated with the first luminescence measuring step of measuring the emission spectrum of the light emitting, with respect to the rare earth complex, the wavelength lambda ₂ light and second irradiation steps, the relative rare earth complex after the second irradiation step, and irradiation with light of wavelength lambda _3, receives the light emission from the rare earth complex, the second luminescence measurement step of measuring the emission spectrum of the light emitting And a calculation step for calculating the intensity of each emission spectrum measured in the first emission measurement step and the second emission measurement step, and identification for identifying identification information associated with the result obtained in the calculation step Including the process Information identification method to butterflies.

  (15) A first calculation step in which the calculation step calculates a ratio of the intensities of line spectra of a plurality of specific wavelengths among the emission spectra measured in the first emission measurement step; and the second emission measurement step. A second calculation step of calculating a ratio of the intensity of the line spectra of the plurality of specific wavelengths among the emission spectra measured in step 1, wherein the identification step corresponds to the ratio calculated in the first calculation step. (14) The information identification method according to (14), wherein identification information attached is identified, and identification information associated with the ratio computed in the second computation stage is further identified.

  (16) The calculation step includes a first calculation step of calculating a ratio of intensity of line spectra of a plurality of specific wavelengths among the emission spectra measured in the first emission measurement step, and the second emission measurement step. Among the emission spectra measured in step 2, the second calculation stage for calculating the ratio of the intensities of the line spectra of the plurality of specific wavelengths, the ratio calculated in the first calculation stage, and the second calculation stage. (14), characterized in that identification information associated with the ratio calculated in the third calculation stage is identified in the identification step. The information identification method described.

(17) When a rare earth complex having a structure in which a photochromic ligand is coordinated to a rare earth ion is excited with light having a wavelength λ ₃ , the emission intensity of light emitted from the rare earth complex is changed to a wavelength λ ₁ and a wavelength λ _2. The light intensity adjustment method characterized by controlling using the light of.

  The rare earth complex according to the present invention has a structure in which a photochromic ligand is coordinated with a rare earth ion. Therefore, there is an effect that light can be emitted by light of a specific wavelength. In addition, there is an effect that the structure can be reversibly changed to the photochromic reaction by using light of two specific wavelengths different from the above-described wavelengths. Furthermore, the emission intensity of light emitted from the rare earth complex according to the present invention can be reversibly changed using the above-described three specific wavelengths.

  An embodiment of the present invention will be described below with reference to FIG. 1, but the present invention is not limited to this.

<I. Rare earth complex according to the present invention>
The rare earth complex according to the present invention is a rare earth complex having a structure in which a photochromic ligand is coordinated to a rare earth ion. In the present specification, the “photochromic ligand” is a compound having photochromic reactivity and capable of coordinating with rare earth ions. “Photochromic reactivity” refers to the property that a single chemical species reversibly changes to two isomers with different absorption spectra by recombination of chemical bonds without changing the molecular weight by the action of light. Say. Therefore, since the two isomers of the photochromic ligand have different molecular structures, not only the absorption spectrum but also various molecular properties such as fluorescence characteristics, refractive index, and dipole moment are different.

In the rare earth complex according to the present invention, the photochromic ligand and the rare earth ion each independently respond to light. In more detail, when irradiated with light of wavelength lambda ₁ in accordance rare earth complex to the present invention, the photochromic ligand structure by a photochromic reaction changes from a first state to a second state. Subsequently, when the light of wavelength λ ₂ is irradiated to the rare earth complex, the photochromic ligand whose structure is changed, that is, the photochromic ligand in the second state, returns to the original molecular structure, that is, the first state. The wavelength λ ₁ and the wavelength λ ₂ are different wavelengths and are characterized by the photochromic ligand. As described above, in the rare earth complex according to the present invention, the molecular structure can be reversibly changed between the first state and the second state by using light of wavelength λ ₁ and wavelength λ ₂ .

On the other hand, when irradiated with light of wavelength lambda ₃ in accordance rare earth complex to the present invention, the rare earth ions are excited to emit light. At this time, the light emission characteristics of the rare earth ions differ depending on the molecular structure of the photochromic ligand, in other words, whether the rare earth complex according to the present invention is in the first state or the second state. In this specification, “the light emission characteristics are different” means that the properties of the light emission component, in other words, the parity is different. For example, “the emission characteristics of rare earth ions are different” means that the relative intensity of the emission intensity of the electric dipole transition is different from the emission intensity of the magnetic dipole transition.

Further, the rare earth complex according to the present invention, the photochromic ligands do not respond to the wavelength lambda ₃ of the light. That is, the light of wavelength lambda _3, the photochromic reaction is not induced. On the other hand, the rare earth ions do not respond to light having the wavelength λ ₁ or λ ₂ . That is, the rare earth ions are excited by light having the wavelength λ ₁ or λ ₂ and do not emit light.

The wavelength λ ₃ is different from the wavelengths λ ₁ and λ ₂ . Thereby, in the rare earth complex according to the present invention, the independence of the photochromic ligand and the rare earth ions with respect to light is maintained. In particular, in the rare earth complex according to the present invention, the wavelength λ ₁ , the wavelength λ ₂ , and the wavelength λ ₃ are wavelengths independent from each other, and the wavelength λ ₃ is longer than the wavelengths λ ₁ and λ _2. Preferably there is. In the present invention, the light of wavelength λ ₁ , wavelength λ _2, and wavelength λ ₃ is not limited to light of a single wavelength, but may be light of a specific wavelength range. In this case, it is preferable that the wavelength ranges of the light beams having the wavelengths λ ₁ , λ _2, and λ ₃ do not overlap, but they may overlap. Specifically, even if the wavelength range of the light that induces the photochromic reaction includes the wavelength range of the excitation light for exciting the rare earth ions, the photochromic ligand in the wavelength range of the excitation light. If the absorbance is small, the photochromic reaction rate of the photochromic ligand by the excitation light is very slow, and substantially no photochromic reaction occurs. Therefore, in the present invention, in addition to the embodiments in which the wavelengths or wavelength ranges of the three types of light are completely different, even if the wavelength ranges of the three types of light overlap, the photochromic reaction of the photochromic ligand is substantially performed. In addition, an embodiment using three types of light in which the light emission of the rare earth ions is not interfered with each other is also included. The relationship between the wavelengths λ ₁ , λ ₂ and λ ₃ is the same in the composition according to the present invention, the information recording / reproducing method, the information identifying method, and the light intensity adjusting method described later.

  Thus, in the rare earth complex according to the present invention, the photochromic ligand and the rare earth ion each independently respond to light. Therefore, the rare earth complex according to the present invention has the following characteristics.

First, the structure of the rare earth complex according to the present invention is reversibly changed between two states by inducing a photochromic reaction using light of wavelength λ ₁ or λ ₂ . In the rare earth complex according to the present invention, the light irradiation method for inducing the photochromic reaction is not particularly limited as long as it can irradiate the light with the wavelength λ ₁ or the wavelength λ ₂ . In general, the structure of the photochromic ligand can be changed by irradiating light of a desired wavelength using a light source such as an LED, deuterium or xenon, a halogen lamp, or a laser.

Second, the rare earth complex according to the present invention, by exciting with light of wavelength lambda _3, emits light. At this time, the method of irradiating the light for exciting the rare earth complex according to the present invention is not particularly limited as long as it can irradiate the light having the wavelength λ ₃ . In general, the rare earth ions can be emitted by irradiating desired excitation light using an excitation light source such as an LED, deuterium, xenon, or halogen lamp.

Thirdly, the rare earth complex according to the present invention is not only different in structure after being irradiated with light of wavelength λ ₁ and after being irradiated with light of wavelength λ ₂ but also excited by light of wavelength λ _3. The emission characteristics of the emitted light are different. In the rare earth complex according to the present invention, the degree of change in the light emission characteristics is not particularly limited, and the light emission characteristics of the rare earth complex after irradiation with light of wavelength λ _{1 and} the light of wavelength λ ₂ are irradiated. It is only necessary that the light emission characteristics of the rare earth complex after being different.

Fourth, rare earth complex according to the present invention, although structures with light having a wavelength lambda ₁ or the wavelength lambda ₂ is changed, are not luminous. On the other hand, the rare earth complex is excited by light of wavelength lambda _3, the light emitting is but the structure is not changed.

Therefore, according to the rare earth complex according to the present invention, it is possible to reversibly change the emission characteristics of light emitted when excited with light of wavelength λ ₃ using light of wavelength λ ₁ and wavelength λ ₂ .

Further, if the characteristics of the rare earth complex according to the present invention are utilized, the light emission characteristics when the rare earth ions are irradiated with light having a wavelength of λ ₃ are evaluated, whereby the rare earth complex according to the present invention has a wavelength λ _1. It is possible to discriminate whether it is a structure when irradiated with the light λ ₂ or a structure when irradiated with the wavelength λ ₂ .

Since the rare earth complex according to the present invention has the above-mentioned characteristics, as shown in FIG. 1, information and signals are input to the photochromic ligand by using light of wavelength λ ₁ and recording (writing) is performed. You can do it. The input or recorded information and signal to the photochromic ligand, by using light having a wavelength lambda _3, the output or can or reproducing (reading). Further, by using the light of the wavelength lambda _2, it is possible to erase the entered or recorded information and signal to the photochromic ligands. Further, since the wavelengths λ ₁ , λ ₂ , and λ ₃ are different from each other, input and recording, output, reproduction, and erasure of information and signals do not buffer each other. Therefore, the rare earth complex according to the present invention can be used as an information recording medium, a nonvolatile memory, and a switching element.

  Moreover, in this invention, the rare earth complex from which the light emission characteristic and the photochromic reactivity were changed variously is realizable by changing the said photochromic ligand, rare earth ions, and its combination variously. Such rare earth complexes each have unique emission characteristics and photochromic reactivity. Therefore, the rare earth complex according to the present invention can itself be used as a code, in other words, as a fingerprint. Specifically, it can be used as an information identification medium such as an ID card.

Furthermore, the emission intensity of the rare earth complex according to the present invention changes when excited with light of wavelength λ ₃ by irradiation with light of wavelength λ ₁ or wavelength λ ₂ . That is, according to the rare earth complex according to the present invention, it is possible to amplify or attenuate light using light. Therefore, the rare earth complex according to the present invention can be applied as a high-speed switch to a control system of an optical amplification device.

  As described above, the structure of the rare earth complex according to the present invention has a structure in which a photochromic ligand is coordinated to a rare earth ion. The rare earth ion includes a ligand other than the photochromic ligand (hereinafter, Also referred to as “other ligands”. Hereinafter, the structure of the rare earth complex according to the present invention, specifically, the rare earth ion, photochromic ligand, and other ligands will be described in detail.

(I-1) Rare earth ion The rare earth ion is not particularly limited as long as it is a rare earth metal ion, but is preferably a trivalent lanthanoid ion, and in particular, Ce ³⁺ , Nd ³⁺ , Sm. More preferably, it is ³⁺ , Eu ³⁺ , Tb ³⁺ , Dy ³⁺ , Er ³⁺ , Pr ³⁺ , Tm ³⁺ , or Yb ³⁺ . If it is the said metal earth ion, stronger light emission can be obtained.

  In the present invention, the excitation wavelength, emission intensity, and emission wavelength of the rare earth complex can be changed by changing the rare earth ions. In addition, the excitation wavelength, emission intensity, and emission wavelength of the rare earth complex according to the present invention can be changed by changing the photochromic ligand or changing the combination of the rare earth ion and the photochromic ligand. Can do. Specifically, in the present invention, the emission wavelength is changed from the visible region to the infrared region by changing rare earth ions and / or photochromic ligands or changing the combination of rare earth ions and photochromic ligands. It can be changed over a wide range up to the region.

(I-2) Photochromic ligand Generally, when a metal ion such as a rare earth ion is present in the vicinity of a photochromic molecule, the photochromic reactivity tends to be remarkably lowered. It is considered that a three-dimensional factor and an electronic factor are additively or synergistically involved in the decrease in photochromic reactivity. Specifically, when a metal ion is present in the vicinity of the photochromic molecule, there is a tendency that the structural change hardly occurs in a three-dimensional structure (steric factor). Further, when a metal ion is present in the vicinity of the photochromic molecule, the speed of electron transfer of the excited photochromic molecule is increased. Therefore, the transition rate from the singlet state to the triplet state of the photochromic molecule increases (electronic factor). It is considered that the photochromic reactivity decreases due to the additive or synergistic action.

  Therefore, the present inventors have intensively studied a photochromic ligand that can eliminate both the above-described three-dimensional factors and electronic factors, and retains photochromic reactivity even when a metal ion is present in the vicinity.

  Furthermore, as described above, the rare earth complex according to the present invention emits rare earth ions when irradiated with excitation light having a specific wavelength. When the rare earth complex according to the present invention is used for applications as described later, the intensity of light emission from the rare earth ions is preferably high. Therefore, the photochromic ligand is preferably one that does not inhibit the light emission of the rare earth ions.

  In general, rare earth ions tend to have lower emission intensity when coordinated with water or a ligand having a flexible structure. Specifically, when the ligand coordinated to the rare earth ions has a flexible structure, the ratio of the energy for exciting the rare earth ions to be released as heat increases. Therefore, since the rare earth ions are not sufficiently excited, the emission intensity is reduced.

  Therefore, the present inventors diligently studied a photochromic ligand that has the smallest possible reduction in the emission intensity of the rare earth ion even when coordinated with the rare earth ion.

  As a result, rare earth ions are present in the vicinity of a photochromic ligand that has a small structural change due to a photochromic reaction, a high reaction rate of the photochromic reaction, and a structure that is as rigid as possible. Even so, the inventors have found that the photochromic reactivity is maintained and that the inhibition of the emission intensity of the rare earth ions is small, and the present invention has been completed.

  Specifically, examples of the photochromic ligand include hexatriene-based molecules. More specifically, the following general formula (1)

Wherein R ₁ and R ₈ are each independently an alkyl group, alkoxyl group, halogen atom, trifluoromethyl group, fluorine-substituted alkyl group, cyano group, hydroxyl group, carboxyl group, sulfonyl group, aryl group or substituted. R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , and R ₇ are each independently a hydrogen atom, alkyl group, alkoxyl group, halogen atom, trifluoromethyl group, fluorine-substituted alkyl Group, cyano group, hydroxyl group, carboxyl group, sulfonyl group, aryl group or substituted aryl group, or R ₂ and R ₃ , R ₃ and R ₄ , R ₄ and R ₅ , or R ₆ and R carbocyclic ring linked to each other and _7, heterocycle, substituted carbocyclic, or forms a substituted _{heterocycle, R 2, R 3, R} 4, _{5, R 6,} and at least one of _{R 7,} include a nitrogen atom, an oxygen atom, a sulfur atom or P = O structure)
The hexatriene type photochromic ligand represented by these can be mentioned.

As described above, in the rare earth complex according to the present invention, the photochromic ligand preferably has a substituent having a rigid structure. Therefore, in the general formula (1), R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , and R ₇ are trifluoromethyl groups, or R ₂ and R ₃ , R ₃ and R ₄ , R ₄ and R ₅ , or R ₆ and R ₇ are preferably linked to each other to form a benzene ring, a thiophene ring, a pyridine, a nitrogen-containing heteroaromatic ring, and a fluorine-substituted product thereof. In the present specification, the “substituent having a rigid structure” is a substituent that is restricted from stretching, bending, and rotating, and is less structurally distorted. System, benzene ring, CF 3, thiophene ring, pyridine, nitrogen-containing heteroaromatic ring, and fluorine-substituted products thereof, fluorinated alkyl groups, and the like. On the other hand, substituents such as methyl groups, ethers, long-chain alkyl chains, amines, alkyl groups, hydroxyl groups, nitro groups, amino groups, and NH-alkyl groups have a high degree of freedom and can easily bend and rotate. Is referred to as a flexible structure substituent.

  As the photochromic ligand, a diarylethene compound can be particularly preferably used among the hexatriene-based molecules. Diarylethene compounds are preferred because they are excellent in thermal irreversibility, have high storage stability under light shielding, and are excellent in repeated durability.

  Specifically, the following general formula (2)

Wherein R ₁ and R ₆ are each independently an alkyl group, alkoxyl group, halogen atom, trifluoromethyl group, fluorine-substituted alkyl group, cyano group, hydroxyl group, carboxyl group, sulfonyl group, aryl group or substituted. R ₂ and R ₅ are each independently a hydrogen atom, alkyl group, alkoxyl group, halogen atom, trifluoromethyl group, fluorine-substituted alkyl group, cyano group, hydroxyl group, carboxyl group, sulfonyl group, An aryl group or a substituted aryl group, wherein R ₃ and R ₄ are each independently a hydrogen atom, alkyl group, alkoxyl group, halogen atom, trifluoromethyl group, fluorine-substituted alkyl group, cyano group, hydroxyl group, carboxyl Group, sulfonyl group, aryl group or substituted aryl group There, or a carbon ring linking R ₃ and R ₄ together, heterocycle, substituted carbocyclic, or forms a substituted heterocycle, X and Y are each independently CH , A nitrogen atom, an oxygen atom, or a sulfur atom, and at least one of R ₂ , R ₃ , R ₄ , R ₅ , X, and Y includes a nitrogen atom, an oxygen atom, or a sulfur atom)
The diarylethene type photochromic ligand represented by these can be mentioned.

In the general formula (2), R ₂ and R ₅ are preferably trifluoromethyl groups, and R ₃ and R ₄ are trifluoromethyl groups, or R ₃ and R ₄ Are preferably connected to each other to form a benzene ring, a thiophene ring, a pyridine, a nitrogen-containing heteroaromatic ring, and a fluorine-substituted product thereof. With such a structure, the photochromic ligand has a rigid structure, a reaction rate of the photochromic reaction is high, and a structural change due to the photochromic reaction is small.

  Furthermore, in the general formula (2), it is preferable that at least one of X and Y is a nitrogen atom, an oxygen atom, or a sulfur atom. If it is such a structure, the said photochromic ligand can be coordinated to the said rare earth ion through X or Y of the said General formula (2).

  Moreover, as said photochromic ligand, following General formula group (3)

(Wherein R ₁ , R ₆ , R ₇ , R ₈ , R ₉ and R ₁₀ are each independently an alkyl group, an alkoxyl group, a halogen atom, a trifluoromethyl group, a fluorine-substituted alkyl group, a cyano group, A hydroxyl group, a carboxyl group, a sulfonyl group, an aryl group or a substituted aryl group, and R ₂ and R ₅ are each independently a hydrogen atom, an alkyl group, an alkoxyl group, a halogen atom, a trifluoromethyl group, or a fluorine-substituted alkyl. Group, cyano group, hydroxyl group, carboxyl group, sulfonyl group, aryl group or substituted aryl group, R ₃ and R ₄ are each independently a hydrogen atom, an alkyl group, an alkoxyl group, a halogen atom, trifluoromethyl. Group, fluorine-substituted alkyl group, cyano group, hydroxyl group, carboxyl group, sulfonyl group, Whether it is Le group or substituted aryl group, or, to form a carbon ring linked R ₃ and R ₄ together, heterocycle, substituted carbocyclic, or a substituted heterocyclic)
And a ligand represented by any of the above. Such a photochromic ligand can coordinate to the rare earth ions.

  Moreover, as a photochromic ligand which can be used suitably in this invention, following General formula (4)

Wherein R ₁ and R ₅ are each independently an alkyl group, alkoxyl group, halogen atom, trifluoromethyl group, fluorine-substituted alkyl group, cyano group, hydroxyl group, carboxyl group, sulfonyl group, aryl group or substituted. R ₂ , R ₃ , and R ₄ are each independently a hydrogen atom, alkyl group, alkoxyl group, halogen atom, trifluoromethyl group, fluorine-substituted alkyl group, cyano group, hydroxyl group, carboxyl group A sulfonyl group, an aryl group or a substituted aryl group)
The ligand represented by these can be mentioned. According to the photochromic ligand, since it has a nitrogen atom that can coordinate to the rare earth ion, it can be more strongly coordinated to the rare earth ion.

  Moreover, as said photochromic ligand, following General formula (7)

Wherein R ₁ and R ₄ are each independently an alkyl group, alkoxyl group, halogen atom, trifluoromethyl group, fluorine-substituted alkyl group, cyano group, hydroxyl group, carboxyl group, sulfonyl group, aryl group or substituted. R ₂ and R ₃ are each independently a hydrogen atom, alkyl group, alkoxyl group, halogen atom, trifluoromethyl group, fluorine-substituted alkyl group, cyano group, hydroxyl group, carboxyl group, sulfonyl group, An aryl group or a substituted aryl group, X and Y are each independently CH, a nitrogen atom, an oxygen atom, or a sulfur atom, and at least one of R ₂ , R ₃ , X, and Y is a nitrogen atom; Including atoms, oxygen atoms, or sulfur atoms)
The ligand represented by these can also be used. In the general formula (7), X and Y are C—R ₅ R ₆ P═O or C—R ₅ C═O (wherein R ₅ and R 6 are each independently an alkyl group, an alkoxyl group, A halogen atom, a trifluoromethyl group, a fluorine-substituted alkyl group, a cyano group, a hydroxyl group, a carboxyl group, a sulfonyl group, an aryl group, or a substituted aryl group).

  In the rare earth complex according to the present invention, the number of coordination of the photochromic ligand to the rare earth ion is not particularly limited. That is, only one photochromic ligand described above may be coordinated to the rare earth ion, or a plurality of the photochromic ligands may be coordinated to the rare earth ion.

  Further, when a plurality of the photochromic ligands are coordinated to one rare earth ion, the photochromic ligands may all be the same, or a plurality of different types of photochromic ligands. They may be coordinated in combination.

  In the present invention, the type of photochromic ligand affects the light emission characteristics of the rare earth ions. That is, if the type of photochromic ligand is different, the emission characteristics of the rare earth ions are different. Furthermore, when the type of photochromic ligand is different, the light wavelength at which the photochromic reaction is induced is different. Therefore, by combining multiple different types of photochromic ligands and coordinating to rare earth ions, it is possible to control light emission characteristics of the rare earth complex according to the present invention in multiple stages using light of multiple wavelengths. It becomes.

(I-3) Other ligands In the rare earth complex according to the present invention, a ligand other than the photochromic ligand may be coordinated with the rare earth ion. Specific examples of such ligands include pyridine and derivatives thereof; nitrogen-containing heterocycles and derivatives thereof; ethylenediamine, nitro, cyano and derivatives thereof; ketones and derivatives thereof; sulfonyl and derivatives thereof; thio compounds and derivatives thereof. Derivatives; and phosphine oxide and its derivatives. Examples of the pyridine and derivatives thereof include the following general formula group (8):

(Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , and R ₈ are each independently an alkyl group, an alkoxyl group, a halogen atom, a trifluoromethyl group, a fluorine-substituted group) An alkyl group, a cyano group, a hydroxyl group, a carboxyl group, a sulfonyl group, an aryl group, or a substituted aryl group, or a carbocycle, a heterocycle, or a substituted carbon bonded to each other between adjacent substituents. Forming a ring or substituted heterocycle)
And a ligand represented by any of the above.

  Examples of the nitrogen-containing heterocycle and derivatives thereof include the following general formula group (9)

(Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , R ₉ , R ₁₀ , R ₁₁ , and R ₁₂ are each independently an alkyl group, alkoxyl Group, halogen atom, trifluoromethyl group, fluorine-substituted alkyl group, cyano group, hydroxyl group, carboxyl group, sulfonyl group, aryl group or substituted aryl group, or linked to each other between adjacent substituents To form a carbocycle, heterocycle, substituted carbocycle, or substituted heterocycle)
And a ligand represented by any of the above.

  Examples of the ethylenediamine, nitro, cyano and derivatives thereof include the following general formula group (10)

(Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , and R ₈ are each independently an alkyl group, an alkoxyl group, a halogen atom, a trifluoromethyl group, a fluorine-substituted group) An alkyl group, a cyano group, a hydroxyl group, a carboxyl group, a sulfonyl group, an aryl group, or a substituted aryl group, or a carbocycle, a heterocycle, or a substituted carbon bonded to each other between adjacent substituents. Forming a ring or substituted heterocycle)
And a ligand represented by any of the above.

  Examples of the ketone and derivatives thereof include the following general formula group (11):

(Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ and R ₆ are each independently an alkyl group, an alkoxyl group, a halogen atom, a trifluoromethyl group, a fluorine-substituted alkyl group, a cyano group, A hydroxyl group, a carboxyl group, a sulfonyl group, an aryl group, or a substituted aryl group, or a carbocyclic ring, a heterocyclic ring, a substituted carbocyclic ring, or a substituted group connected to each other between adjacent substituents. Forming a heterocycle)
And a ligand represented by any of the above.

  Examples of the sulfonyl and derivatives thereof include the following general formula group (12)

(Wherein R ₁ and R ₂ are each independently an alkyl group having 1 to 8 carbon atoms, a fluorine-substituted alkyl group having 1 to 8 carbon atoms, or a phenyl group)
And a ligand represented by any of the above.

  Examples of the thio compound and derivatives thereof include the following general formula group (13):

(Wherein R ₁ , R ₂ , R ₃ , R ₄ , and R ₅ are each independently an alkyl group having 1 to 8 carbon atoms, a fluorine-substituted alkyl group having 1 to 8 carbon atoms, or a phenyl group. )
And a ligand represented by any of the above.

  Examples of the phosphine oxide and derivatives thereof include the following general formula group (14):

(Wherein R ₁ , R ₂ , R ₃ , and R ₄ are each independently an alkyl group having 1 to 8 carbon atoms, a fluorine-substituted alkyl group having 1 to 8 carbon atoms, or a phenyl group)
And a ligand represented by any of the above.

  By coordinating such a ligand, the synthesis of the rare earth complex according to the present invention can be facilitated, the solubility in a solvent can be enhanced, and the stability of the rare earth complex can be enhanced.

  Specific examples of the rare earth complex according to the present invention in which the above photochromic ligand and other ligands are coordinated to the rare earth ion include the following general formula (6):

Wherein R ₁ and R ₅ are each independently an alkyl group, alkoxyl group, halogen atom, trifluoromethyl group, fluorine-substituted alkyl group, cyano group, hydroxyl group, carboxyl group, sulfonyl group, aryl group or substituted. R ₂ , R ₃ , and R ₄ are each independently a hydrogen atom, alkyl group, alkoxyl group, halogen atom, trifluoromethyl group, fluorine-substituted alkyl group, cyano group, hydroxyl group, carboxyl group , A sulfonyl group, an aryl group or a substituted aryl group, wherein R ₅ and R ₆ are each independently an alkyl group having 1 to 8 carbon atoms, a fluorine-substituted alkyl group having 1 to 8 carbon atoms, or a phenyl group. Ln is a rare earth ion, n is an integer of 1 to 5, m is an integer of 0 to 4, and the sum of n and m 5 is less than or equal to.)
The rare earth complex represented by these can be mentioned.

  The method for producing such a rare earth complex according to the present invention is not particularly limited, and a suitable production method is appropriately selected from conventionally known methods according to the ligand coordinated to the rare earth complex, What is necessary is just to use in combination.

<2. Composition according to the present invention>
The composition concerning this invention is a composition containing the rare earth complex concerning this invention mentioned above and a medium. The above-mentioned composition may contain the rare earth complex according to the present invention described above alone, or may contain a mixture of a plurality of types of rare earth complexes. In the composition according to the present invention, the content of the rare earth complex according to the present invention is not particularly limited, and is appropriately set according to the use and the type of the medium.

Thus, the composition according to the present invention contains the rare earth complex according to the present invention. Therefore, the composition according to the present invention exhibits specific photoresponsiveness with respect to _three different wavelengths (wavelength λ ₁ , wavelength λ ₂ , and wavelength λ ₃ ). Specifically, the compositions according to the present invention, by irradiating light of wavelength lambda _3, emits light. This is because the irradiation rare earth ions of the wavelength lambda ₃ of the light rare earth complex contained in the composition, is excited, it is by emitting. In the composition according to the present invention, the light emission characteristics of light emitted by irradiation with light of wavelength λ ₃ can be reversibly changed by using light of wavelengths λ ₁ and λ ₂ . This is because the molecular structure of the photochromic ligand of the rare earth complex contained in the composition is reversibly changed by the photochromic reaction induced by the light having the wavelength λ ₁ and the wavelength λ _2. .

  Therefore, the composition concerning this invention can be utilized for the information recording medium for recording or memorize | storing information and a signal similarly to the rare earth complex concerning this invention. Moreover, the composition according to the present invention can be used for an information identification medium such as an ID card by utilizing the light emission characteristics of the composition according to the present invention and the characteristics in which the light emission characteristics are changed by a photochromic reaction. . Specifically, the rare earth complex according to the present invention has different emission characteristics and photochromic reactivity depending on the type of photochromic ligand and rare earth ions constituting the rare earth complex. Therefore, the rare earth complex according to the present invention can function as a code. This code can be deciphered based on the light emission characteristics of the rare earth complex and the change in the light emission characteristics due to the photochromic reaction. Therefore, the composition containing the rare earth complex according to the present invention as a code can be used as an information identification medium.

Furthermore, the composition according to the present invention can change light emission characteristics, in other words, light emission intensity, using light having a wavelength λ ₁ or λ ₂ . That is, the composition according to the present invention can amplify or attenuate light at high speed using light. Therefore, the composition according to the present invention can also be used as a switching element such as a high-speed switch. Such a switching element can also be applied to a control system of an optical amplifying device. That is, application to optical information communication is also possible.

  The medium contained in the composition according to the present invention is not particularly limited, and a suitable medium may be appropriately selected and used according to the use of the composition.

  Specific examples of the medium include organic solvents, resins, inorganic materials, and organic-inorganic hybrid materials.

  Examples of the organic solvent include aromatic hydrocarbon solvents such as benzene, toluene, xylene, ethylbenzene, trimethylbenzene, diethylbenzene, and isopropylbenzene; aliphatic hydrocarbon solvents such as alkanes and cycloalkanes; Halogenated hydrocarbon solvents such as 1,2-dichloroethane, tetrachloroethane, trichloroethylene, methyl iodide, chloroform, carbon tetrachloride, chlorobenzene, dichloronaphthalene; acetone, methyl ethyl ketone, methyl isobutyl ketone, diethyl ketone, diisobutyl ketone, cyclopentanone , Cyclohexanone and other ketone solvents; diethyl ether, dimethoxyethane, diethoxyethane, tetrahydrofuran, tetrahydropyran and other ether solvents; acetic acid Esters such as chill, ethyl acetate, butyl acetate, isoamyl acetate, ethyl formate, butyl formate, cellosolve acetate, carbitol acetate; methanol, ethanol, isopropyl alcohol, butanol, cellosolve, ethyl cellosolve, butyl cellosolve, carbitol, ethylcarby Examples thereof include alcohol solvents such as tol, butyl carbitol and diacetone alcohol. These organic solvents may be used alone or in combination.

  As the resin, polyimide resin, polyamide resin, polymethyl methacrylic resin, polyacrylate, polystyrene resin, polyethylene naphthalate resin, polyester resin, polyurethane, polycarbonate resin, epoxy resin, polyethylene terephthalate resin, Examples thereof include vinyl chloride resins, vinylidene chloride resins, acrylonitrile butadiene styrene (ABS) resins, acrylonitrile styrene (AS) resins, cycloolefin resins, siloxane polymers, and halides or deuterides thereof. These resins may be used alone or in combination of two or more.

  Examples of the inorganic material include glass produced by a sol-gel method.

  As described above, in the composition according to the present invention, the medium as exemplified above can be used, but it is preferable to use a medium having high compatibility with the rare earth complex according to the present invention.

  Furthermore, you may further add the additive for providing a specific function to the composition concerning this invention according to the use. Examples of such additives include additives such as antioxidants, inorganic fillers, stabilizers, antistatic agents, dyes, pigments, flame retardants, inorganic fillers, and elastomers for improving impact resistance. it can. Further, for the purpose of improving the processability of the composition according to the present invention, additives such as a lubricant can be added. Further, when a cast film is formed by casting the composition according to the present invention, a leveling agent may be added to the composition according to the present invention.

  Examples of the antioxidant include 2,6-di-t-butyl-4-methylphenol, 2,2′-dioxy-3,3′-di-t-butyl-5,5′-dimethylphenylmethane. Tetrakis [methylene-3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane, 1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) Butane, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl-benzene, stearyl-β- (3,5-di-t-butyl-4 -Hydroxyphenyl) propionate, 2,2'-dioxy-3,3'-di-t-butyl-5,5'-diethylphenylmethane, 3,9-bis [1,1-dimethyl-2- [β- (3-t-butyl-4- Droxy-5-methylphenyl) propionyloxy] ethyl], 2,4,8,10-tetraoxospiro [5,5] undecane, tris (2,4-di-t-butylphenyl) phosphite, cyclic neo Pentanetetraylbis (2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetraylbis (2,6-di-t-butyl-4-methylphenyl) phosphite, 2,2-methylenebis And (4,6-di-t-butylphenyl) octyl phosphite.

  Examples of the inorganic filler include calcium carbonate, carbon fiber, and metal oxide.

  Examples of the leveling agent include a fluorine-based nonionic surfactant, a special acrylic resin leveling agent, and a silicone leveling agent.

  The shape of the composition according to the present invention is not particularly limited, and may be any shape. For example, shapes such as plate, powder, granule, granule, paste, liquid, and emulsion can be mentioned.

  The manufacturing method of the composition concerning this invention is not specifically limited, What is necessary is just to select a suitable method suitably according to the composition, its shape, a use, etc. For example, when the composition is a powder, the rare earth complex according to the present invention, the medium, and, if necessary, other additives as exemplified above may be added using a twin screw extruder, Brabender, roll kneader, or the like. It can be produced by a method of mixing and pelletizing using an extruder, or a method of further pulverizing pellets with a pulverizer to form a powder.

  In addition, when the composition is in a liquid state, it can be obtained by dissolving or dispersing the rare earth complex according to the present invention, the medium, and, if necessary, other additives as exemplified above in an appropriate solvent. Can be manufactured.

  Hereinafter, utilization of the composition concerning this invention is demonstrated. The composition according to the present invention includes, for example, a memory element, an information recording medium, and an optical memory that can be suitably used for an information recording / reproducing method described later, and an information identification such as an ID card that can be suitably used for an information identifying method described later. Medium: It can be suitably used to produce a high-speed switching element that can be used in the optical amplification method described later.

  Here, an information recording medium using the composition will be described as one embodiment of use of the composition according to the present invention.

  Specific examples of such an information recording medium include an information recording medium in which a recording layer is formed on both sides or one side of a substrate.

  In the information recording medium according to the present invention, for example, the recording layer may contain the composition according to the present invention. The recording layer preferably has a thickness of 0.01 μm to 3.0 mm, more preferably 0.05 μm to 1.0 mm. When the thickness of the recording layer is less than 0.01 μm, the recording display performance of the recording layer may not be sufficiently exhibited. On the other hand, when the thickness of the recording layer exceeds 3.0 mm, it may be difficult to form a smooth recording layer over the entire surface.

  Examples of the substrate include polymethyl methacrylic resin, polystyrene resin, polyethylene terephthalate resin, polyethylene naphthalate resin, polycarbonate resin, polyamide resin, vinyl chloride resin, vinylidene chloride resin, acrylonitrile butadiene styrene ( An ABS resin, an acrylonitrile styrene (AS) resin, a thermoplastic resin such as a cycloolefin resin, glass, paper, or the like can be used.

  The manufacturing method of such an information recording medium is not particularly limited. For example, it is produced by casting a solution of the composition according to the present invention on the substrate and forming a recording layer on the substrate by subjecting the obtained solution layer to a solvent removal treatment. be able to. The method for casting the composition on a substrate is not particularly limited, and can be performed using a conventionally known method such as a bar coater.

  Moreover, it can also manufacture by forming the coating film of the composition concerning this invention in the surface of the said board | substrate. The method for forming the coating film of the composition according to the present invention on the surface of the substrate is not particularly limited, and a conventionally known method can be used. For example, brush coating method, dip coating method, spray coating method, plate coating method, spinner coating method, bead coating method, wet coating method such as curtain coating method, gravure printing method, screen printing method, offset printing method, letterpress printing method, etc. Can be mentioned.

  Furthermore, the information recording medium can be produced by molding the composition according to the present invention so that the substrate and the recording layer are integrally formed, or a film made of the composition according to the present invention can be formed on the substrate. It can also be manufactured by laminating. Specifically, for example, the information recording medium can be produced by molding the composition as a composition obtained by mixing the rare earth complex according to the present invention and the resin exemplified as the medium. In the information recording medium, a surface protective film or the like may be provided on the recording layer.

  Furthermore, the composition according to the present invention can be used in the form of a liquid. For example, by encapsulating a solution composition according to the present invention in which a rare earth complex according to the present invention is dissolved in a suitable solvent (for example, a solvent exemplified as being usable in production) in a glass cell or the like, information is obtained. It can be used as a recording medium.

  The information identification medium and the high-speed switching element can also be manufactured by appropriately selecting a method suitable for each.

<III. Information recording and playback method>
As described above, the rare earth complex according to the present invention can be suitably used for applications for recording and reproducing information. Therefore, the present invention includes an information recording / reproducing method using the rare earth complex according to the present invention. Further, the present invention includes an information recording medium and a molecular memory used for the method, and an information recording / reproducing apparatus for performing the method.

  As described above, the information recording medium and the molecular memory according to the present invention can be manufactured by processing the composition according to the present invention.

  Here, the information recording / reproducing method according to the present invention will be described in detail.

The information recording / reproducing method according to the present invention records information on the photochromic ligand by irradiating light having a wavelength λ ₁ to a rare earth complex having a structure in which the photochromic ligand is coordinated to a rare earth ion. Step (hereinafter also referred to as “recording step”), irradiating the rare earth complex with light of wavelength λ ₃ , receiving light emitted from the rare earth complex, measuring the emission intensity of the emitted light, and measuring the measured light emission And a step of reproducing the information recorded in the photochromic ligand (hereinafter also referred to as “regeneration step”) based on the emission intensity of the other specific configurations are particularly limited. is not. Information recording and reproducing method according to the present invention, in addition to the recording process and reproducing process, further, by irradiating light of wavelength lambda ₂ in the rare earth complex to erase the information recorded on the photochromic ligand A process (hereinafter also referred to as “erase process”) may be included. Hereinafter, the recording process, the reproducing process, and the erasing process will be described in detail.

In (III-1) recording step the recording process, the rare earth complex according to the present invention, by irradiating light of wavelength lambda _1, the structure of the photochromic ligands of the rare earth complex from the first state to the second state Change. By utilizing this structural change, information can be recorded on the photochromic ligand. When recording information on an information recording medium according to the present invention described above, by irradiating light of wavelength lambda ₁ that focused to the recording layer, the rare earth complex according to the present invention in a irradiated portion of the information recording medium Change the structure of the photochromic ligand and record information.

The wavelength λ ₁ is not particularly limited, and is determined by the type of the photochromic ligand. Preferably, light in the ultraviolet region is used. In addition, the method of irradiating light with wavelength λ _{1 in} the recording step is not particularly limited. For example, a method using a deuterium lamp, a xenon lamp, a mercury lamp, a halogen lamp, an LED, a laser, or the like can be given.

In the recording step, the time for irradiating the light with the wavelength λ _{1 to} the rare earth complex is not particularly limited. For example, irradiation may be performed for 1 picosecond or longer.

(III-2) Regeneration Step In the regeneration step, the rare earth complex according to the present invention is irradiated with light having a wavelength λ ₃ to cause the rare earth complex to emit light. Then, the emission intensity of the emitted light is measured, and the information recorded in the photochromic ligand in the recording step is reproduced based on the emission intensity. More specifically, in the reproduction step, first, the light with the wavelength λ ₃ is irradiated to the rare earth complex on which information is recorded in the recording step. Thereby, the rare earth complex is excited and emits light. Next, in the regeneration step, the emission intensity of the emitted light is measured. Based on the measured emission intensity, it is determined whether the photochromic ligand of the rare earth complex is in the first state or the second state. Thereby, the information recorded in the rare earth complex is reproduced.

When reproducing information recorded on an information recording medium according to the present invention, by irradiating light of wavelength lambda ₃ that is focused to the recording layer, from the rare earth complex molecules in the irradiated portion of the information recording medium The luminescence intensity of the luminescence is measured. Next, based on the measured emission intensity of each rare earth complex, it is determined whether the photochromic ligand of each rare earth complex is in the first state or the second state. Thereby, the information recorded on the information recording medium is reproduced.

The wavelength λ ₃ is not particularly limited, and is determined by the type of the rare earth ion. Further, in the above regeneration step, a method of irradiating light of wavelength lambda ₃ is not particularly limited. For example, a method using a deuterium lamp, a xenon lamp, a mercury lamp, a halogen lamp, an LED, a laser, or the like can be given.

In the recording step, the time for irradiating the light with the wavelength λ _{3 to} the rare earth complex is not particularly limited. For example, irradiation may be performed for 1 picosecond or longer.

  In the present specification, “measuring the emission intensity of emitted light” means measuring the intensity of the entire emission that has not been spectrally measured, measuring the intensity of the spectral emission spectrum, and having a specific wavelength of the spectral emission spectrum. It is meant to include all of measuring only the intensity of the line spectrum. That is, in the regeneration step, the intensity of the entire emission may be measured without spectrally analyzing the emission from the rare earth complex, or the intensity of the emission spectrum obtained by spectroscopy of the emission may be measured. Only the intensity of the line spectrum of a specific wavelength of the emission spectrum may be measured.

  In the regeneration step, the configuration for measuring the intensity of the entire light emission can simplify the configuration of the apparatus for measuring the emission intensity, and at the same time reduce the time required for the regeneration step. If the intensity of the emission spectrum obtained by separating the emitted light is measured, the accuracy of identifying information can be improved. Furthermore, if only the intensity of the line spectrum of a specific wavelength of the spectral emission spectrum is measured, the apparatus configuration for measuring the emission intensity can be simplified, and at the same time, the time required for the regeneration process can be reduced. Further, the accuracy of identifying information can be improved.

  In the reproducing step of the information recording / reproducing method according to the present invention, only the emission intensity of a line spectrum having a specific wavelength of the emission spectrum obtained by separating the emission from the rare earth complex or the information recording medium can be measured. preferable. In this case, the number of wavelengths to be selected is not particularly limited, and may be one or may be two or more. By increasing the number of wavelengths to be selected, the accuracy of reproducing information can be further improved. For example, if two wavelengths are selected, whether the structure of the photochromic ligand of the rare earth complex is in the first state or the second state using the ratio of the line spectrum intensities of the two wavelengths. Can be determined. Therefore, information can be reproduced with higher accuracy. If two wavelengths are selected, the time required for the regeneration process can be shortened. Therefore, information can be read out at higher speed.

  Further, the wavelength to be selected may be appropriately selected according to the emission characteristics of the type of rare earth complex or information identification medium to be used, and is not particularly limited. For example, the wavelength of light emission by magnetic dipole transition or light emission by electric dipole transition can be selected. In particular, in the present invention, it is preferable to select both wavelengths of light emission due to magnetic dipole transition and light emission due to electric dipole transition. In addition, the wavelength of the light emission by the said magnetic dipole transition and the light emission by an electric dipole transition is determined by the kind of rare earth complex.

  Further, the structure of the photochromic ligand can be determined, for example, by comparing the emission intensity measured in the regeneration step with the emission intensity associated with the first state and the emission intensity associated with the second state. It can be done by comparing with.

  Here, “compare emission intensity” means a configuration in which the intensity of the entire emission from the rare earth complex is measured in the regeneration step, and the emission intensity is associated with the first state. It means that the intensity is compared with the emission intensity associated with the second state.

  On the other hand, when the intensity of the emission spectrum obtained by separating the emission is measured, (1) the intensity of the emission spectrum measured in the regeneration step is changed to the emission spectrum associated with the first state, and the second Comparing the intensity of the emission spectrum associated with the state, and (2) calculating the ratio of the intensity of the line spectra of a plurality of specific wavelengths in the emission spectrum measured in the regeneration step, It means comparing with the ratio associated with the first state and the ratio associated with the second state. According to the latter, the reproduction speed can be increased and at the same time the reproduction accuracy can be increased.

  Furthermore, in the case of a configuration in which only the intensity of a line spectrum of a specific wavelength of the emission spectrum obtained by spectroscopy in the regeneration step is measured, “compare emission intensity” means that a plurality of line spectra measured in the regeneration process are measured. It means that the respective intensities are compared with the respective intensities of the line spectrum associated with the first state and the line spectrum associated with the second state. In addition, when measuring the intensity of a line spectrum of a plurality of specific wavelengths in the reproduction step, in addition to the above meaning, calculate the ratio of the intensity of the line spectrum measured in the reproduction step, It means comparing the ratio with the ratio associated with the first state and the ratio associated with the second state. According to the latter, the reproduction speed can be increased and at the same time the reproduction accuracy can be increased.

  In the present invention, when the ratio of line spectrum intensities is calculated, the ratio may be the ratio of the intensity of two line spectra, or the ratio of the intensity of three or more line spectra. Also good. By calculating the ratio of the intensity of more line spectra, the reproduction accuracy can be improved.

In such information recording and reproduction method according to the present invention, the use of a rare earth complex or information recording medium according to the present invention, by irradiating light of wavelength lambda ₂ to the rare earth complex, the structure of the photochromic ligands second state As long as the state is not changed to the first state, information is not erased from the rare earth complex or the information recording medium. Therefore, the information recorded on the rare earth complex or the information recording medium can be reproduced repeatedly.

In (III-3) erasing step the erasing step, the rare earth complex according to the present invention, by irradiating light of wavelength lambda _2, the first state a structure of photochromic ligands of the rare earth complex from the second state Change. Thus, the information recorded on the photochromic ligand can be erased by changing the structure of the photochromic ligand. To erase the information recorded on the information recording medium according to the present invention, it can be erased by irradiating the entire recording layer, the wavelength lambda ₂ light.

The wavelength λ ₂ is not particularly limited, and is determined by the type of the photochromic ligand. Preferably, light in the visible region is used. In addition, the method of irradiating light with wavelength λ _{2 in} the erasing process is not particularly limited. For example, a method using a deuterium lamp, a xenon lamp, a mercury lamp, a halogen lamp, an LED, a laser, or the like can be given.

In the erasing step, the time for irradiating the rare earth complex with light having a wavelength λ ₂ is not particularly limited. For example, irradiation may be performed for 1 picosecond or longer.

  Information can be recorded again on the rare earth complex and the information recording medium from which the recorded information has been erased in the recording step. That is, information can be repeatedly recorded and erased on the rare earth complex and the information recording medium according to the present invention.

As described above, according to the information recording / reproducing method of the present invention, information is recorded, reproduced, and erased by using the rare earth complex according to the present invention and the light of wavelength λ ₁ , wavelength λ ₂ , and wavelength λ _3. Can be repeated. Note that the wavelength λ ₁ , the wavelength λ ₂ , and the wavelength λ ₃ are different from each other.

  The present invention also includes an information recording / reproducing apparatus including a constituent member for executing the above steps of the information recording / reproducing method according to the present invention. In addition, the information recording / reproducing apparatus concerning this invention should just be provided with the structural member which can implement said each process, The concrete structure is not specifically limited. For example, the configuration of the information recording / reproducing apparatus according to the present invention includes a light source unit for performing the recording step; a light source unit, a light receiving unit, a light emission intensity measuring unit, and a light emission intensity calculating unit for performing the reproduction step. A configuration including a light source unit for performing the erasing step may be mentioned.

<IV. Information identification method>
As described above, the rare earth complex according to the present invention has a function as a code. Therefore, the present invention includes an information identification method using the rare earth complex according to the present invention. Further, the present invention includes an information identification medium used for the method and an information identification apparatus for performing the method.

  The shape and form of the information identification medium are not particularly limited. Specifically, the information identification medium according to the present invention can be in the shape and form of, for example, a card, a film, a seal, and an armband formed by molding a resin containing the rare earth complex according to the present invention. In addition, images, figures, and characters printed or printed using the ink containing the rare earth complex according to the present invention can be used as the information identification medium.

  Moreover, the kind of rare earth complex contained in the information identification medium according to the present invention may be one kind or a plurality of kinds, but a plurality of kinds is preferably contained. Thereby, discrimination power (security) can be made higher. Such an information identification medium according to the present invention can be manufactured by processing the composition according to the present invention as described above.

  Here, the information identification method according to the present invention will be described in detail.

The information identification method according to the present invention is a step of irradiating light having a wavelength λ ₁ to a rare earth complex having a structure in which a photochromic ligand is coordinated to a rare earth ion (hereinafter also referred to as “first irradiation step”). And a step of irradiating the rare earth complex after the first irradiation step with light having a wavelength λ ₃ , receiving light emitted from the rare earth complex, and measuring the light emission intensity of the light emission (hereinafter referred to as “first light emission”). Measurement step), a step of irradiating the rare earth complex with light having a wavelength λ ₂ (hereinafter also referred to as a “second irradiation step”), and a rare earth complex after the second irradiation step. , irradiated with light of wavelength lambda _3, it receives the light emission from the rare earth complex, measuring the emission intensity of the light emitting (hereinafter, also referred to as "second light emission measuring step") and, the first light measuring step And the respective emission intensities measured in the second emission measurement step. A calculation step (hereinafter also referred to as “calculation step”) and a step of identifying identification information associated with the result obtained in the calculation step (hereinafter also referred to as “identification step”). The other specific configurations are not particularly limited.

  Here, the said 1st irradiation process, 1st light emission measurement process, 2nd irradiation process, 2nd light emission measurement process, a calculation process, and an identification process are demonstrated in detail.

In (IV-1) first irradiation step the first irradiation step, the rare earth complex according to the present invention, by irradiating light of wavelength lambda _1, the structure of the photochromic ligands of the rare earth complex from the first state Change to the second state. When the information identification medium according to the present invention is used, the information identification unit of the information identification medium is irradiated with the focused light having the wavelength λ ₁ by irradiating the information identification unit containing the rare earth complex according to the present invention. The structure of the photochromic ligand of the rare earth complex according to the present invention is changed.

The wavelength λ ₁ is not particularly limited, and is determined by the type of the photochromic ligand. Preferably, light in the ultraviolet region is used. Moreover, the method of irradiating light with wavelength λ ₁ in the first irradiation step is not particularly limited. For example, a method using a deuterium lamp, a xenon lamp, a mercury lamp, a halogen lamp, an LED, a laser, or the like can be given.

In the first irradiation step, the time for irradiating the rare earth complex with light having a wavelength λ ₁ is not particularly limited. For example, irradiation may be performed for 1 picosecond or longer.

(IV-2) First Luminescence Measurement Step In the first luminescence measurement step, first, light (excitation light) having a wavelength λ ₃ is irradiated to the rare earth complex or the information identification medium after the first irradiation step. Thereby, the rare earth complex or the information identification medium emits light. Next, the emitted light is received and the intensity of the emitted light is measured.

The wavelength λ ₃ is not particularly limited, and is determined by the type of the rare earth ion. Further, in the above regeneration step, a method of irradiating light of wavelength lambda ₃ is not particularly limited. For example, a method using a deuterium lamp, a xenon lamp, a mercury lamp, a halogen lamp, an LED, a laser, or the like can be given.

In the recording step, the time for irradiating the light with the wavelength λ _{3 to} the rare earth complex is not particularly limited. For example, irradiation may be performed for 1 picosecond or longer.

  Further, in the first emission measurement step, the intensity of the entire emission may be measured without dispersing the emission from the rare earth complex, or the intensity of the emission spectrum obtained by spectroscopy of the emission may be measured. Alternatively, only the intensity of the line spectrum of a specific wavelength of the spectral emission spectrum may be measured.

  In the first luminescence measurement step, the configuration for measuring the intensity of the entire luminescence from the rare earth complex can simplify the apparatus configuration for measuring the luminescence intensity, and at the same time, the first luminescence measurement step. Can be shortened. If the intensity of the emission spectrum obtained by separating the emitted light is measured, the accuracy of identifying information can be improved. Furthermore, if only the intensity of the line spectrum of the specific wavelength of the spectral emission spectrum is measured, the apparatus configuration for measuring the emission intensity can be simplified, and at the same time, the first emission measurement step is performed. The time required can be shortened, and further, the accuracy of identifying information can be improved.

  In the first emission measurement step of the information identification method according to the present invention, only the intensity of the line spectrum of a specific wavelength of the emission spectrum obtained by spectrally dividing the emission from the rare earth complex or the information identification medium is measured. Is preferred. In this case, the number of wavelengths to be selected is not particularly limited, and may be one or may be two or more. By increasing the number of wavelengths to be selected, the accuracy of identifying information can be further improved. For example, if two wavelengths are selected, the ratio of the intensities of the line spectra of these two wavelengths can be calculated in a calculation process described later, and information can be identified in the identification process described later using the ratio. it can. Therefore, information can be identified with higher accuracy. Further, if two wavelengths are selected, the time required for the first light emission measurement step and the calculation step described later can be shortened. Therefore, the processing time of the information identification method according to the present invention can be shortened.

  Further, the wavelength to be selected may be appropriately selected according to the emission characteristics of the type of rare earth complex or information identification medium to be used, and is not particularly limited. For example, the wavelength of light emission by magnetic dipole transition or light emission by electric dipole transition can be selected. In particular, in the present invention, it is preferable to select both wavelengths of light emission due to magnetic dipole transition and light emission due to electric dipole transition. In addition, the wavelength of the light emission by the said magnetic dipole transition and the light emission by an electric dipole transition is determined by the kind of rare earth complex.

(IV-3) Second Irradiation Step In the second irradiation step, the rare earth complex according to the present invention is irradiated with light having a wavelength λ ₂ to change the structure of the photochromic ligand in the rare earth complex from the second state. Change to the first state. When the information identification medium according to the present invention is used, the information identification unit of the information identification medium is irradiated with light having a wavelength λ ₂ that is focused on the information identification unit containing the rare earth complex according to the present invention. The structure of the photochromic ligand of the rare earth complex according to the present invention is changed.

The wavelength λ ₂ is not particularly limited, and is determined by the type of the photochromic ligand. Preferably, light in the visible region is used. In addition, the method of irradiating light with wavelength λ ₂ in the second irradiation step is not particularly limited. For example, a method using a deuterium lamp, a xenon lamp, a mercury lamp, a halogen lamp, an LED, a laser, or the like can be given.

In the second irradiation step, the time for irradiating the rare earth complex with light having a wavelength λ ₂ is not particularly limited. For example, irradiation may be performed for 1 picosecond or longer.

(IV-4) second light-emitting measuring step the second emission measuring step, except that irradiation with wavelength lambda ₃ of the light (excitation light) to the rare earth complex or information identification medium after the second irradiation step This is the same as the first luminescence measurement step. Therefore, detailed description thereof is omitted here.

(IV-5) Calculation Step In the calculation step, the light emission intensity measured in the first light emission measurement step and the second light emission measurement step is calculated. For example, when measuring the intensity of the entire light emission from the rare earth complex in the first light emission measurement step and the second light emission measurement step, the ratio of the light emission intensities of both is calculated.

  Further, when measuring the intensity of an emission spectrum obtained by spectroscopy of the emission from the rare earth complex in the first emission measurement step and the second emission measurement step, a plurality of the spectrum intensities measured in the first emission measurement step are used. The ratio of the intensity of the line spectrum of the specific wavelength is calculated (hereinafter also referred to as “first calculation stage”). Further, among the intensities of the spectrum measured in the second light emission measurement step, the ratio of the intensities of the line spectra of a plurality of specific wavelengths that are the same as those in the first calculation stage is calculated (hereinafter referred to as the “second calculation stage”). Say). In addition, a ratio between the ratio calculated in the first calculation stage and the ratio calculated in the second calculation stage may be calculated (hereinafter also referred to as “third calculation stage”). In the first calculation stage and the second calculation stage, the number of line spectra to be selected is not particularly limited, and may be two or three or more. By increasing the number, information identification accuracy can be increased. In the first calculation stage and the second calculation stage, it is preferable to select a line spectrum of light emission due to magnetic dipole transition and light emission due to electric dipole transition.

  Furthermore, when measuring only the intensity of the line spectrum of a specific wavelength of the emission spectrum obtained in the first emission measurement step and the second emission measurement step, the ratio of the intensity of the corresponding line spectrum is calculated. In the first luminescence measurement step and the second luminescence measurement step, when measuring the intensity of the line spectra of a plurality of wavelengths, the ratio of the intensity of the plurality of line spectra measured in the first luminescence measurement step, and The ratios of the intensities of the plurality of line spectra measured in the two-emission measurement process are respectively calculated (“first calculation stage” and “second calculation stage”). Further, the ratio of the calculated ratios may be calculated (“third calculation stage”).

(IV-6) Identification Step In the identification step, identification information associated with the ratio calculated in the calculation step is identified. Specifically, the identification information associated with the ratio calculated in at least one of the first calculation stage, the second calculation stage, and the third calculation stage may be identified. At this time, in consideration of the identification accuracy, it is preferable to identify the identification information associated with the ratio calculated in two stages among the first calculation stage, the second calculation stage, and the third calculation stage, More preferably, the identification information associated with the ratio is identified in all three stages.

  In the embodiment in which the intensity of the entire light emission from the rare earth complex is measured in the first light emission measurement step and the second light emission measurement step and the ratio of the light emission intensities is calculated in the calculation step, the identification step Then, what is necessary is just to identify the identification information matched with the ratio.

The above “identification information associated with the calculated ratio” means the following. Each of the rare earth complexes according to the present invention has unique photochromic reactivity and light emission characteristics. That is, each of the rare earth complexes according to the present invention exhibits a unique response to the wavelength λ ₁ , the wavelength λ ₂ , and the wavelength λ ₃ . Therefore, the ratio calculated in the above calculation step is a value unique to each rare earth complex. Therefore, the above ratio can be associated with a rare earth complex having the ratio. In other words, the “identification information associated with the calculated ratio” may refer to the rare earth complex corresponding to the ratio. Moreover, if the rare earth complex specified by the calculated ratio is used as a cipher, any information can be encrypted using the rare earth complex. Therefore, the identification information includes any information encrypted by such a rare earth complex.

  An information identification method according to the present invention specifies (identifies) a rare earth complex or a rare earth complex contained in an information identification medium by utilizing both the photochromic characteristics and the light emission characteristics of the rare earth complex according to the present invention. The identification information associated with the complex is identified and authenticated. Therefore, this is an information identification method having an unprecedented high level of discrimination power (security).

  Further, in the information identification method according to the present invention, since the substance is specified by the light intensity or the light intensity ratio, the identification can be performed even when the rare earth complex is deteriorated. There are no restrictions on usage conditions. In addition, since rare earth complexes are colorless and transparent, they are invisible under normal conditions, and have better security. Furthermore, when a single rare earth ion is used, it is possible to recover rare earth ions, which are valuable resources even after use.

  In addition, the present invention includes an information identification device including a constituent member for executing the above steps of the information identification method according to the present invention. In addition, the information identification apparatus concerning this invention should just be provided with the structural member which can implement said each process, and the specific structure is not specifically limited. For example, the information recording / reproducing apparatus according to the present invention includes a light source unit for performing the first irradiation step; a light source unit for performing the first light emission measurement step, a light receiving unit, a light emission intensity calculation unit; A light source unit for performing an irradiation step; a light source unit for performing a second light emission measurement step, a light receiving unit, a light emission intensity calculation unit; a light emission intensity analysis unit for performing a calculation step; and an identification unit for performing an identification step The structure provided is mentioned.

<V. Light intensity adjustment method>
The rare earth complex according to the present invention can amplify light at high speed by light. Therefore, the present invention also includes a light intensity adjustment method using the rare earth complex according to the present invention. Furthermore, the present invention includes an optical switch used in the method and an optical amplifying apparatus including the optical switch.

  The optical switch according to the present invention only needs to contain the rare earth complex according to the present invention, and other configurations, shapes, and the like are not particularly limited. Such an optical switch can be manufactured by using the composition according to the present invention.

  Here, the light intensity adjustment method according to the present invention will be described in detail.

Light intensity adjustment method according to the present invention, when the photochromic ligand excited by light with a wavelength lambda ₃ to the rare earth complex having a structure coordinated to rare earth ions, the intensity of the emitted radiation from the rare earth complex, wavelength Any method may be used as long as it is a control method using light of λ ₁ and wavelength λ ₂ , and other specific configurations are not particularly limited.

  That is, the light intensity adjusting method is a method of amplifying or attenuating light with light based on the characteristics of the rare earth complex according to the present invention described above.

  According to the light intensity adjusting method according to the present invention, light is amplified or attenuated by light, so that light can be amplified or attenuated at a very high speed. Therefore, the light intensity adjustment method according to the present invention can be used for a control system of an optical amplification device. That is, it can be applied to high-speed switching of optical information communication.

  The present invention is not limited to the configurations described above, and various modifications can be made within the scope of the claims, and the technical means disclosed in different embodiments are appropriately combined. The obtained embodiment is also included in the technical scope of the present invention.

  The present invention will be described more specifically based on Examples and FIG. 2 and FIG. 3, but the present invention is not limited to this. Those skilled in the art can make various changes, modifications, and alterations without departing from the scope of the present invention.

[Example 1: Synthesis of [Eu (THIA) ₂ (HFA) ₃ ]]
[Eu (THIA) ₂ (HFA) ₃ ] was synthesized by reacting [Eu (HFA) ₃ (OH ₂ ) ₂ ] with t-thiazole. Hereinafter, the synthesis method of [Eu (THIA) ₂ (HFA) ₃ ] will be described in detail.

  First, t-thiazole was synthesized by the following method.

(1) Synthesis of t-thiazole (1-1) Synthesis of 5-methyl-2-phenyl-4- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) thiazole Synthesis (1-1-1) Substrate synthesis

  Thiobenzamide (20 g, 142 mmol) was dissolved in 60 ml of ethyl acetate. 2-bromopropanoic acid (25 g, 163 mmol) was added, and the mixture was stirred at room temperature for 24 hours. The solid produced by vacuum filtration was collected and washed with diethyl ether. As a result, yellow solid 1 (18 g, yield: 43%) was obtained.

  (1-1-2) Synthesis of 5-methyl-2-phenylthiazol-4-one

  While stirring, 57 ml of pyridine was cooled to 0 ° C. or lower, and the above yellow solid 1 (13 g, 45 mmol) as a substrate was gradually added. When the mixture was stirred for 15 minutes, water was added and the product was recovered by filtration under reduced pressure. Purification was performed by recrystallization with hot methanol. As a result, yellow needle-like crystals 2 (6.3 g, yield: 73%) were obtained.

  The yellow needle crystal 2 thus obtained was subjected to NMR spectrum measurement and confirmed to be 5-methyl-2-phenylthiazol-4-one. The results of NMR spectrum measurement are shown below.

¹ H NMR (300 MHz, CDCl ₃ ) σ = 2.33 (s, 3H), 7.43 (m, 3H), 7.83 (m, 2H).
(1-1-3) Synthesis of 4-Bromo-5-methyl-2-phenylthiazol

5-methyl-2-phenylthiazol-4-one (14.5 g, 76 mmol) and POBr ₃ (50 g, 174 mmol) were placed in a 300 ml four-necked flask and heated and stirred at 90 ° C. After 2 hours and 30 minutes, the reaction was stopped because the red solution solidified. Ethyl acetate and water were added to the reaction solution to quench the reaction. The mixture was neutralized with an aqueous sodium hydroxide solution, extracted with ethyl acetate, dried over magnesium sulfate, and evaporated under reduced pressure. Purification by silica chromatography using ethyl acetate: hexane = 1: 10 as a developing solvent gave the target white solid 3 (yield: 14 g, yield: 72%).

  The white solid 3 thus obtained was subjected to NMR spectrum measurement and confirmed to be 4-Bromo-5-methyl-2-phenylthiazol. The results of NMR spectrum measurement are shown below.

¹ H NMR (300 MHz, CDCl ₃ ) σ = 2.44 (s, 3H), 7.43 (m, 3H), 7.87 (m, 2H).
Synthesis of (1-1-4) 5-methyl-2-phenyl-4- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) thiazole

  A 500 ml four-necked flask containing 4-Bromo-5-methyl-2-phenylthiazol (4 g, 16 mmol) was flame-dried, purged with nitrogen, and anhydrous ether was added. After cooling to −60 ° C., n-BuLi (12 ml, 19 mmol) was added dropwise. The mixture was stirred for 1 hour while maintaining the temperature. 2-isopropoxy-4,4 ′, 5,5′-tetramethyl-1,3,2-dioxaborolane (5 ml, 19 mmol) was added dropwise. The mixture was stirred for 1 hour while maintaining the temperature. It returned to room temperature and stirred overnight. After stopping the reaction, the reaction mixture was neutralized with hydrochloric acid, extracted with ethyl acetate, dried over magnesium sulfate, and evaporated under reduced pressure. Thereby, a yellowish white solid 4 was obtained. The yellowish white solid 4 thus obtained was subjected to NMR spectrum measurement to give 5-methyl-2-phenyl-4- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) thiazole. It was confirmed that. The results of NMR spectrum measurement are shown below.

¹ H NMR (300 MHz, CDCl ₃ ) σ = 1.38 (s, 12H), 2.73 (s, 3H), 7.36 (m, 3H), 7.95 (m, 2H).
(1-2) Synthesis of 4,5-dibromo-2-phenylthiazole (1-2-1) Synthesis of substrate

  Bromoacetic acid (18.5 g, 133 mmol) was dissolved in 60 ml of ethyl acetate. Thiobenzamide (18.2 g, 133 mmol) was dissolved in 190 ml of ethyl acetate. Thiobenzamide-ethyl acetate solution was added to bromoacetic acid-ethyl acetate solution and stirred at room temperature for 24 hours. After 24 hours, a precipitate was formed in the reaction vessel and was collected by filtration. The residue was washed with diethyl ether. As a result, white solid 5 (yield: 32 g, yield: 87%) was obtained.

  (1-2-1) Synthesis of 4-hydoroxy-2-phenylthiazol

  The substrate, white solid 5 (32 g, 116 mmol), was dissolved in 80 ml of pyridine and stirred for 10 minutes. Ten minutes later, ice water was added and precipitation occurred. The precipitate was filtered and the residue was washed with ice water. The collected precipitate was reprecipitated with hot ethanol. As a result, 4-hydoroxy-2-phenylthiazol, a yellow solid 6 (yield: 10.2 g, yield: 49%) was obtained.

  (1-2-2) Synthesis of 4,5-dibromo-2-phenylthiazole

4-hydoroxy-2-phenylthiazol ( 1.77 g, 10 mmol), POBr 3 (13 g, 45 mmol), pyridine hydrobromide (3.26 g, 20.3 mmol) was heated and stirred at 110 ° C.. The reaction was stopped after 24 hours. The reaction solution was diluted with ethyl acetate and then neutralized with an aqueous sodium hydroxide solution. The reaction solution was extracted with ethyl acetate. The organic layer was dried over magnesium sulfate, filtered and evaporated under reduced pressure. Purification by silica column chromatography (ethyl acetate: hexane = 1: 15) gave the target compound 7 (yield: 0.73 g, yield: 23%).

  The thus obtained target product 7 was measured for NMR spectrum and confirmed to be 4,5-dibromo-2-phenylthiazole. The results of NMR spectrum measurement are shown below.

¹ H NMR (300 MHz, CDCl ₃ ) σ = 7.45 (m, 3H), 7.85 (m, 2H).
(1-3) Synthesis of t-thiazole

4,5-dibromo-2-phenylthiazole (0.73g, 2.3mmol), 5-methyl-2-phenyl-4- (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) thiazole (5.7 mmol, 2.5 eq) was placed in a 100 ml four-necked flask and dissolved in 60 ml of dioxane. 9 ml of 2M-K ₃ PO ₄ aqueous solution was added and stirred. Nitrogen bubbling was performed for 30 minutes. Pd (pph ₃ ) ₄ (0.14 mmol, 6 mol%) and triphenylphosphine (0.23 mmol, 10 mol%) were added, and the mixture was heated and stirred at 90 ° C. for 3 days. Purification was performed 4 times by alumina column chromatography (ethyl acetate: hexane = 1: 10). As a result, compound 8 (yield: 0.78 g, yield: 67%) was obtained.

  Compound 8 thus obtained was subjected to NMR spectrum measurement and mass spectrometry, and confirmed to be t-thiazole. The results of NMR spectrum measurement and mass spectrometry are shown below.

¹ H NMR (300 MHz, CDCl ₃ ) σ = 2.11 (s, 3H), 2.52 (s, 3H), 7.33 (m, 3H), 7.43 (m, 6H), 7.80 (m, 2H), 7.93 (m , 2H), 8.07 (m, 2H).
ESI-Mass (m / z) = 508.1 (M ⁺ + H)
[Eu (THIA) ₂ (HFA) ₃ ] was synthesized using t-thiazole synthesized as described above and [Eu (HFA) ₃ (OH ₂ ) ₂ ].

(2) Synthesis of [Eu (THIA) ₂ (HFA) ₃ ]

[Eu (HFA) ₃ (OH ₂ ) ₂ ] (607 mg, 0.75 mmol) was dissolved in 15 ml of methanol. After adding 38 ml of chloroform to the reaction solution, t-thiazole (380 mg, 0.75 mmol) was added and dissolved. The reaction solution was heated to reflux for 36 hours. After stopping the reaction, the reaction solution was distilled off under reduced pressure. When chloroform was added, a small amount of insoluble component was confirmed, and this was removed by filtration. When the filtrate was distilled off under reduced pressure and hot hexane was added to the resulting solid, it was separated into an insoluble component and a soluble component. The solution was removed by decantation. When this operation was repeated twice, a light green powder 9 (yield: 0.38 g, yield: 28%) was obtained.

The light green powder 9 thus obtained was subjected to elemental analysis, NMR spectrum measurement, mass spectrometry, and IR spectrum measurement, and confirmed to be [Eu (THIA) ₂ (HFA) ₃ ]. The results of elemental analysis, NMR spectrum measurement, mass spectrometry, and IR spectrum measurement are shown below.

Anal. Found: C, 48.32; H, 2.70; N, 4.76%.
Calcd.for C ₇₃ H ₄₅ N ₆ O ₆ S ₆ F ₁₈ Eu ・ H ₂ O: C, 48.54; H, 2.62; N, 4.65%.
¹ H NMR (300 MHz, CDCl ₃ ) σ = 2.11 (s, 3H), 2.53 (s, 3H), 7.42 (m, 3H), 7.43 (m, 6H), 7.80-8.10 (m, 6H).
ESI-Mass (m / z) = 1581.07 (M ⁺ ).
IR (KBr) = 3421 w, 3062 m, 3024 m, 1654 s, 1558 m, 1531 m, 1475 s, 1255 s, 1205 s, 1146 s.
[Example 2: Reversible change in structure of [Eu (THIA) ₂ (HFA) ₃ ]]
The absorption spectrum of [Eu (THIA) ₂ (HFA) ₃ ] obtained in Example 1 was measured. The result is shown by a solid line in FIG.

Next, [Eu (THIA) ₂ (HFA) ₃ ] was irradiated with light (ultraviolet light) having a wavelength of 365 nm for 5 seconds, and then an absorption spectrum was measured. The result is shown by a broken line in FIG.

As shown in FIG. 2, the absorption spectrum changed between before and after irradiating [Eu (THIA) ₂ (HFA) ₃ ] with light (ultraviolet light) having a wavelength of 365 nm. This change in the absorption spectrum indicates that the structure of [Eu (THIA) ₂ (HFA) ₃ ] is changed by irradiation with light (ultraviolet rays) having a wavelength of 365 nm.

[Eu (THIA) ₂ (HFA) ₃ ] is irradiated with light (ultraviolet light) having a wavelength of 365 nm for 5 seconds, and further irradiated with light (visible light) having a wavelength of 440 nm or more for 5 minutes. As a result, the [Eu (THIA) ₂ (HFA) ₃ ] coincided with the absorption spectrum before irradiation with light (ultraviolet rays) having a wavelength of 365 nm. This indicates that [Eu (THIA) ₂ (HFA) ₃ ] whose structure is changed by light (ultraviolet light) having a wavelength of 365 nm is restored to its original structure by light (visible light) having a wavelength of 440 nm or more.

Thus, in Example 2, [Eu (THIA) ₂ (HFA) ₃ ] is reversibly obtained by using light with a wavelength of 365 nm (ultraviolet light) and light with a wavelength of 440 nm or more (visible light). It became clear that the structure could be changed.

[Example 3: Luminous properties of [Eu (THIA) ₂ (HFA) ₃ ]]
An emission spectrum was measured when [Eu (THIA) ₂ (HFA) ₃ ] obtained in Example 1 was excited with excitation light having a wavelength of 465 nm. Similarly, the emission spectrum of [Eu (THIA) ₂ (HFA) ₃ ] after irradiation with light (ultraviolet light) having a wavelength of 365 nm for 5 seconds was also measured. Each obtained emission spectrum was normalized so that the emission intensity of the magnetic dipole transition (590 nm) was 1.

As a result, as shown in FIG. 3A, the emission intensity of the electric dipole transition (615 nm) in [Eu (THIA) ₂ (HFA) ₃ ] (solid line in FIG. 3A) has a wavelength of 365 nm. It was higher than the emission intensity of [Eu (THIA) ₂ (HFA) ₃ ] after irradiation with light (ultraviolet light) (broken line in FIG. 3A). This indicates that the nature of the luminescent component from the rare earth ions, that is, the parity has changed. Furthermore, considering this together with the result of Example 2, the structure of [Eu (THIA) ₂ (HFA) ₃ ] is changed by irradiation with light (ultraviolet rays) having a wavelength of 365 nm, and accordingly, the electric bipolar is changed. It shows that the emission intensity of the child transition (615 nm) changes.

[Eu (THIA) ₂ (HFA) ₃ ] is irradiated with light (ultraviolet light) having a wavelength of 365 nm for 5 seconds, and further irradiated with light (visible light) having a wavelength of 440 nm or more for 5 minutes. When the emission spectrum was measured in the same manner, [Eu (THIA) ₂ (HFA) ₃ ] coincided with the emission spectrum before irradiating light (ultraviolet rays) having a wavelength of 365 nm. This corresponds to the reversible structural change of [Eu (THIA) ₂ (HFA) ₃ ] due to light having a wavelength of 365 nm (ultraviolet light) and light having a wavelength of 440 nm or more (visible light), and [Eu (THIA) ₂ (HFA) ₃ ] shows a reversible change in light emission characteristics.

Furthermore, the emission spectrum of [Eu (THIA) ₂ (HFA) ₃ ] when light with a wavelength of 365 nm (ultraviolet light) and light with a wavelength of 440 nm or more (visible light) are alternately and continuously irradiated is the same as described above. It measured on condition of this. As a result, as shown in FIG. 3B, the emission intensity of the electric dipole transition (615 nm) when the emission intensity of the magnetic dipole transition (590 nm) is 1, the light (ultraviolet light) having a wavelength of 365 nm or the wavelength In response to irradiation with light (visible light) of 440 nm or more, it increased or decreased reversibly. This is by irradiating alternately _{[Eu (THIA) 2 (HFA} ) 3] with respect to the wavelength 365nm light (UV) and wavelength 440nm or more light (visible light), [Eu (THIA) ₂ It shows that the structure of (HFA) ₃ ] can be reversibly changed any number of times.

In addition, even if [Eu (THIA) ₂ (HFA) ₃ ] is irradiated with light (excitation light) having a wavelength of 465 nm for 120 seconds, the emission spectrum of [Eu (THIA) ₂ (HFA) ₃ ] changes. Was not seen. This means that the structure of [Eu (THIA) ₂ (HFA) ₃ ] changes depending on the light having a wavelength of 365 nm (ultraviolet light) or the light having a wavelength of 440 nm or more (visible light), but the light having a wavelength of 465 nm (excitation light). Indicates that the structure does not change.

From the results of the above examples, it has been clarified that [Eu (THIA) ₂ (HFA) ₃ ] can be reversibly changed in structure using light of two different wavelengths. Moreover, it became clear that the light emission characteristics reversibly change with this reversible structural change. This change in the light emission characteristics was not due to a simple change in the light emission intensity, but was due to a change in the nature of the light emission component from the rare earth ions, that is, the parity. That is, it became clear that [Eu (THIA) ₂ (HFA) ₃ ] can reversibly control the emission characteristics of rare earth ions.

  Note that the present invention is not limited to the configurations described above, and various modifications are possible within the scope of the claims, and technical means disclosed in different embodiments and examples respectively. Embodiments and examples obtained by appropriately combining them are also included in the technical scope of the present invention. Moreover, all the academic literatures and patent literatures described in this specification are incorporated herein by reference.

  As described above, in the present invention, since the photochromic ligand is coordinated with the rare earth ion, the light emission characteristic of the rare earth ion can be controlled using the photochromic characteristic of the photochromic ligand. Therefore, the present invention can be used for a recording medium and a storage medium such as a nonvolatile molecular memory, and a recording apparatus and a storage apparatus including the recording medium. Further, the present invention can also be used for an information identification medium such as a security encryption body in which an optical signal is encrypted, an information identification device using the same, and an information identification system. Furthermore, the present invention can be applied to a switch such as a high-speed switch for optical information communication, an optical amplifying apparatus including the switch, and a control system for the optical amplifying apparatus.

It is a figure which shows typically the principle of the information recording / reproducing method using the rare earth complex concerning this invention. It is a figure which shows the absorption spectrum of [Eu (THIA) ₂ (HFA) ₃ ] in the Example of this invention. FIG. 3A is a diagram showing an emission spectrum of [Eu (THIA) ₂ (HFA) ₃ ] in the example of the present invention, and FIG. 3B is a diagram showing [Eu (THIA) in the example of the present invention. It is a figure which shows the reversibility of the luminescent property of ₂ ) (HFA) ₃ ].

Claims (12)

Under following general formula (4)

Wherein R ₁ and R ₅ are each independently an alkyl group, alkoxyl group, halogen atom, trifluoromethyl group, fluorine-substituted alkyl group, cyano group, hydroxyl group, carboxyl group, sulfonyl group, aryl group or substituted. R ₂ , R ₃ , and R ₄ are each independently a hydrogen atom, alkyl group, alkoxyl group, halogen atom, trifluoromethyl group, fluorine-substituted alkyl group, cyano group, hydroxyl group, carboxyl group A sulfonyl group, an aryl group or a substituted aryl group)
Rare earth complexes you characterized in that in the photochromic ligand represented has a structure coordinated to the rare earth ion. The following general formula group (5)

(Wherein R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , R ₈ , R ₉ , R ₁₀ , R ₁₁ , and R ₁₂ are each independently an alkyl group, alkoxyl Group, halogen atom, trifluoromethyl group, fluorine-substituted alkyl group, cyano group, hydroxyl group, carboxyl group, sulfonyl group, aryl group or substituted aryl group, or linked to each other between adjacent substituents To form a carbocycle, heterocycle, substituted carbocycle, or substituted heterocycle)
The rare earth complex according to claim 1, wherein the ligand represented by any one of the above is further coordinated to the rare earth ion. The following general formula (6)

Wherein R ₁ and R ₅ are each independently an alkyl group, alkoxyl group, halogen atom, trifluoromethyl group, fluorine-substituted alkyl group, cyano group, hydroxyl group, carboxyl group, sulfonyl group, aryl group or substituted. R ₂ , R ₃ , and R ₄ are each independently a hydrogen atom, alkyl group, alkoxyl group, halogen atom, trifluoromethyl group, fluorine-substituted alkyl group, cyano group, hydroxyl group, carboxyl group , A sulfonyl group, an aryl group or a substituted aryl group, wherein R ₅ and R ₆ are each independently an alkyl group having 1 to 8 carbon atoms, a fluorine-substituted alkyl group having 1 to 8 carbon atoms, or a phenyl group. Ln is a rare earth ion, n is an integer of 1 to 5, m is an integer of 0 to 4, and the sum of n and m 5 is less than or equal to.)
Rare earth complex represented by The rare earth complex according to claim 1 or 3 , wherein the rare earth ion is a trivalent lanthanoid ion. The rare earth ^{ions, Ce 3+, Nd 3+, Sm} 3+, Eu 3+, Tb 3+, Dy 3+, Er 3+, Pr 3+, according to claim 1 or 3, wherein the ^{Tm 3+,} or ^{Yb 3+} Rare earth complex. A composition for producing an information recording medium , comprising the rare earth complex according to any one of claims 1 to 5 and a medium. By irradiating light of wavelength lambda ₁ with respect to rare earth complex according to any one of claims 1 to 5, a recording step of recording information on the photochromic ligand,
Irradiating light of wavelength λ ₃ to the rare earth complex, receiving light emitted from the rare earth complex, measuring emission intensity of the emission, and recording on the photochromic ligand based on the measured emission intensity of the emission And a reproducing step of reproducing the recorded information. An information recording / reproducing method comprising: 8. The information recording / reproducing method according to claim 7 , further comprising an erasing step of erasing information recorded on the photochromic ligand by irradiating the rare earth complex with light having a wavelength [lambda] ₂ . A first irradiation step of irradiating the rare earth complex according to any one of claims 1 to 5 with light having a wavelength λ ₁ ;
Against rare earth complex after the first irradiation step, and irradiation with light of wavelength lambda _3, a first luminescence measuring step of receiving the emission from the rare earth complex, measuring the emission spectrum of the light emitting,
A second irradiation step of irradiating the rare earth complex with light having a wavelength λ ₂ ;
Against rare earth complexes after the second irradiation step, and irradiation with light of wavelength lambda _3, and the second luminescence measuring step of receiving the emission from the rare earth complex, measuring the emission spectrum of the light emitting,
A calculation step of calculating the intensity of each emission spectrum measured in the first emission measurement step and the second emission measurement step;
An identification step of identifying identification information associated with the result obtained in the calculation step. The above calculation process is
A first calculation step of calculating a ratio of intensity of line spectra of a plurality of specific wavelengths among the emission spectra measured in the first emission measurement step;
A second calculation step of calculating a ratio of the line spectra of the plurality of specific wavelengths among the emission spectra measured in the second emission measurement step,
In the identification process,
Identifying identification information associated with the ratio computed in the first computation stage,
The information identification method according to claim 9 , further comprising identifying identification information associated with the ratio calculated in the second calculation stage. The above calculation process is
A first calculation step of calculating a ratio of intensity of line spectra of a plurality of specific wavelengths among the emission spectra measured in the first emission measurement step;
A second calculation step of calculating the ratio of the line spectra of the plurality of specific wavelengths among the emission spectra measured in the second emission measurement step;
A third calculation stage for calculating a ratio between the ratio calculated in the first calculation stage and the ratio calculated in the second calculation stage;
In the identification process,
10. The information identification method according to claim 9 , wherein identification information associated with the ratio calculated in the third calculation step is identified. When excited rare earth complex according with light having a wavelength lambda ₃ to any one of claims 1 to 5, the emission intensity of the emitted radiation from the rare earth complexes, using light having a wavelength lambda ₁ and wavelength lambda ₂ And controlling the light intensity.

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