JP2005128152A - Composition and nonlinear optical material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nonlinear optical material which has an excellent nonlinear optical constant and can be utilized suitably to an optical switch, an optical element and the like. <P>SOLUTION: The nonlinear optical material has, on a substrate, aligned dye associate and ionic liquid. The dye associate is preferably a J-associate and the ionic liquid is preferably an imidazolium salt compound or a compound having an iodonium ion as a counter-ion. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a composition containing a dye aggregate and an ionic liquid and a nonlinear optical material using the composition.

Many researches have been made in the past because the dye aggregate exhibits properties different from those in the monomer state. Usually, as a dye aggregate, a substance whose maximum absorption wavelength of the association band is shifted to a longer wavelength side than the dye monomer is a J-aggregate, and a substance where the maximum absorption wavelength is shifted to a shorter wavelength side than the dye monomer is an H-aggregate. Call it. In particular, J-aggregates are widely used as spectral sensitizing dyes in silver halide light-sensitive materials because they give sharper absorption bands than monomer-state absorption bands.
Further, since the J-aggregate has a large dipole moment, it has been proposed that it can be used as an optical element, for example, a nonlinear optical element or an optical switch. Specifically, a method for forming a J aggregate orientation dispersed film useful as a nonlinear optical element on a substrate by polarization orientation of a meso J aggregate having a giant static multipole in a base material such as PVA (See, for example, Patent Document 1) and a method of forming a dye aggregate thin film on a solid substrate using a specific squarylium dye derivative and using it as an optical switch material (see, for example, Patent Document 2). ) Etc. have been proposed. In particular, as the nonlinear optical material has a larger dipole, its nonlinear optical constant increases and an excellent optical element with high responsiveness is obtained. Although the optical element having a certain degree of responsiveness can be obtained by using the dye-aggregate thin film, problems such as changes in the association state with time have occurred, and the level has not yet reached a level that is practically satisfactory.
From the viewpoint of applying the dye aggregate to various functional materials, it has been desired to develop a dye aggregate in a medium having unprecedented characteristics.
JP 2001-151904 A Japanese Patent Application Laid-Open No. 11-282034

  The present invention has been made in view of the above-described problems, and has a dye aggregate and a composition having excellent nonlinearity, and an excellent nonlinear optical constant by using the composition. It is an object of the present invention to provide a nonlinear optical material that can be suitably used for a switch, an optical element, or the like.

As a result of investigations, the present inventors have found that the above-mentioned problem can be solved by arranging oriented dye aggregates in a specific ionic liquid medium, and have completed the present invention.
That is, the composition of the present invention is characterized by containing a dye aggregate and an ionic liquid.
Here, the dye aggregate is preferably a J-aggregate or an H-aggregate, and more preferably a J-aggregate.
Moreover, it is a preferable aspect that the dye in the dye aggregate is at least one selected from a cyanine dye, a merocyanine dye, and an oxonol dye.
The ionic liquid used for the medium preferably has an imidazolium salt compound or an iodonium ion as a counter ion, and particularly preferably an imidazolium salt compound.

Furthermore, the nonlinear optical material according to claim 5 of the present invention is characterized by having the composition of the present invention on a substrate.
In arranging the dye aggregate on the substrate, a substrate oriented by rubbing is preferably used, and the dye aggregate is preferably linearly oriented on the substrate.

  The dye used in the present invention is preferably a compound represented by the following general formula (1).

一般式（１）

General formula (1)

In the formula, Z ¹ represents an atomic group necessary for forming a nitrogen-containing heterocycle. However, these may be further condensed with a ring. R ¹ represents an alkyl group. Q ¹ represents a group necessary for the compound represented by the general formula (I) to form a methine dye. L ¹ and L ² represent a methine group. p ¹ represents 0 or 1. M ¹ represents a counter ion for charge balance, and m ¹ represents a number of 0 or more necessary for neutralizing the charge of the molecule.

The composition of the present invention has a dye aggregate and an ionic liquid, and by using this, has an excellent nonlinear optical constant, and can be suitably used for nonlinear optical materials such as optical switches and optical elements. There is an effect.
Further, the composition and the nonlinear optical material of the present invention can exist stably without leaving the ionic liquid as a solvent volatilizing even if left in an open system in the air.

  Hereinafter, the present invention will be described in detail. In the present specification, “to” indicates a range including numerical values described before and after the values as a minimum value and a maximum value, respectively.

(Composition)
The composition of the present invention is a composition having a dye aggregate and an ionic liquid.

(Non-linear optical material)
The nonlinear optical material of the present invention having the composition of the present invention is a nonlinear optical material characterized by having a dye aggregate and an ionic liquid on a substrate. FIG. 1 is a model diagram showing one embodiment of the nonlinear optical material of the present invention. FIG. 1 is a model diagram, and the nonlinear optical material of the present invention is not limited to the illustrated embodiment. In FIG. 1, each element represents a relative positional relationship and does not represent an absolute position, and the size of each illustrated element is relative and absolute. Not something. The nonlinear optical material 10 of the present invention includes a substrate 12 and an ionic liquid layer 14 formed on the substrate 12, and an oriented dye aggregate 16 exists in the ionic liquid layer 14. .

(substrate)
The substrate used in the present invention is not particularly limited, and any substrate used as a substrate of a nonlinear optical material such as a glass substrate, a quartz substrate, and a silicon substrate can be used, but is formed on the substrate. From the viewpoint of stably holding without reacting with the ionic liquid constituting the ionic liquid layer, the material is preferably a glass substrate or a quartz substrate.
In addition, the thickness of the substrate used in the present invention is not particularly limited, but is 0.05 mm to 10 mm, more preferably 0.1 mm to 1.0 mm from the viewpoint of transmitting light without loss. It is preferable.

  The surface of the substrate according to the present invention has been rubbed from the viewpoint of stably holding the liquid without reacting with the ionic liquid of the present invention and / or from the viewpoint of easy orientation of the dye aggregate of the present invention. Is preferred. The rubbing treatment referred to here is preferably a treatment for forming irregularities in a certain direction by rubbing the polymer film with a cloth or a brush.

(Ionic liquid)
The nonlinear optical material of the present invention is characterized by using an ionic liquid together with a dye aggregate. The ionic liquid means an ionic compound composed of a cationic compound and an anionic compound and is a liquid. An ionic liquid is a volatile compound corresponding to a vapor pressure, whereas an ionic liquid is expected to be used as a solvent for a functional material as a non-volatile liquid having no vapor pressure. Up to now, as an application of an ionic liquid, for example, Japanese Patent Application Laid-Open No. 2003-123791 has proposed an application to an electrolyte of a battery. However, a combination with a dye aggregate and an application of a nonlinear optical material have been studied in the past. There are no examples.

When such a special ionic liquid is used as a medium for a dye aggregate, compared with the case where a known PVA or the like is used, (1) since there is no evaporation of the solvent, the stability over time is excellent. (2) There are advantages such as high dielectric constant and advantageous for association of dyes.
The ionic liquid used in the present invention may be any ionic liquid as long as it is composed of an ionic compound, but from the viewpoint of chemical stability, preferably an imidazolium salt compound, a pyridinium salt compound, or an ammonium salt. Compounds, phosphonium salt compounds and the like.

  Specific examples of the ionic liquid according to the present invention include 1-ethyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium bromide, 1-ethyl-3-methylimidazolium iodide, 1-ethyl-3-methylimidazolium bromide, 1-ethyl-3-methylimidazolium bromide, Ethyl-3-methylimidazolium trifluoromethanesulfonate, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium hexafluorophosphate, 1-n-butyl-3-methylimidazolium chloride, 1-n-butyl-3-methylimidazolium bromide, 1-n-butyl-3-methylimidazolium tetrafluoroborate, octyltriphenylphosphonium tosylate, octyltriphenylphosphonium chloride, octyl riff Examples include phenylphosphonium bromide, methyltributylammonium tosylate, methyltributylammonium chloride, and methyltributylammonium bromide.

  The ionic liquid according to the present invention is preferably a heterocyclic compound that is not three-dimensionally bulky from the viewpoint of promoting the formation of dye aggregates. Preferably, it is an imidazolium salt compound. More preferred are 1-ethyl-3-methylimidazolium salt compounds and 1-n-butyl-3-methylimidazolium salt compounds. As the ionic liquid used in the present invention, those having a halogen ion as a counter ion are preferred, and an iodo ion is particularly preferred from the viewpoint of promoting the formation of an association of dyes.

(Dye used for dye aggregate)
The dye used in the dye aggregate of the present invention may be any dye, for example, cyanine dye, styryl dye, hemicyanine dye, merocyanine dye, trinuclear merocyanine dye, tetranuclear merocyanine dye, rhodacyanine dye, complex Cyanine dye, complex merocyanine dye, allopolar dye, oxonol dye, hemioxonol dye, squalium dye, croconium dye, azamethine dye, azo dye, anthraquinone dye, perylene dye, phthalocyanine dye, diketopyrrolopyrrole dye, naphthoquinoline dye, streptocyanine Examples thereof include dyes, styryl dyes, and chelate dyes.

  As the dye of the present invention, a chromophore having a large transition dipole moment is preferable from the viewpoint of use in a nonlinear optical material. This is because the nonlinear optical constant depends on the polarization of the compound, and the chromophore having a large transition dipole moment has a higher polarizability, and therefore gives a larger nonlinear optical constant. Examples of such chromophores having a large transition dipole moment include cyanine dyes, merocyanine dyes, and oxonol dyes.

  As the dye of the present invention, a cyanine dye and / or a merocyanine dye can be suitably used. The general formula of the above dye is preferably those shown in (XI) and (XII) of US Pat. No. 5,340,694, columns 21-22. However, the number of n12, n15, n17, and n18 is not limited and is an integer of 0 or more. For more information on these dyes, see FMHarmer, “Heterocyclic Compounds-Cyanine Dyes and Related Compounds”, John Willie &・ John Wiley & Sons-New York, London, 1964, DMSturmer "Heterocyclic Compounds-Special Topics in Heterocyclic Compounds-Special topics in cyclic chemistry) ”, Chapter 18, Section 14, 482-515 Mitsugu.

  As the dye for forming the dye aggregate according to the present invention, a cyanine dye, a merocyanine dye, and an oxonol dye are preferable, and a cyanine dye is particularly preferable.

  More specifically, the dye according to the present invention is preferably a compound represented by the following general formula (1).

一般式（１）

General formula (1)

In the formula, Z ¹ represents an atomic group necessary for forming a nitrogen-containing heterocycle. However, these may be further condensed with a ring. R ¹ represents an alkyl group. Q ¹ represents a group necessary for the compound represented by the general formula (I) to form a methine dye. L ¹ and L ² represent a methine group. p ¹ represents 0 or 1. M ¹ represents a counter ion for charge balance, and m ¹ represents a number of 0 or more necessary for neutralizing the charge of the molecule.

Z ¹ represents an atomic group necessary for forming a nitrogen-containing heterocyclic ring. However, the nitrogen-containing heterocycle may further have a condensed ring. Examples of the nitrogen-containing heterocycle include thiazoline nucleus, thiazole nucleus, benzothiazole nucleus, oxazoline nucleus, oxazole nucleus, benzoxazole nucleus, selenazoline nucleus, selenazole nucleus, benzoselenazole nucleus, 3,3-dialkylindolenine nucleus (for example, 3, 3-dimethylindolenine), imidazoline nucleus, imidazole nucleus, benzimidazole nucleus, 2-pyridine nucleus, 4-pyridine nucleus, 2-quinoline nucleus, 4-quinoline nucleus, 1-isoquinoline nucleus, 3-isoquinoline nucleus, imidazo [4 , 5-b] quinoxaline nucleus, oxadiazole nucleus, thiadiazole nucleus, tetrazole nucleus, pyrimidine nucleus, etc., preferably benzothiazole nucleus, benzoxazole nucleus, 3,3-dialkylindolenine nucleus (for example, 3,3-dimethylindolenine), Nzoimidazole nucleus, 2-pyridine nucleus, 4-pyridine nucleus, 2-quinoline nucleus, 4-quinoline nucleus, 1-isoquinoline nucleus, 3-isoquinoline nucleus, more preferably benzothiazole nucleus, benzoxazole nucleus, 3 , 3-dialkylindolenine nucleus (for example, 3,3-dimethylindolenine), benzimidazole nucleus, particularly preferably benzoxazole nucleus, benzothiazole nucleus, benzimidazole nucleus, most preferably benzoxazole nucleus, Benzothiazole nucleus.

  These nitrogen-containing heterocycles may further have a substituent. If the substituent that can be introduced here is V, the substituent V is not particularly limited. For example, a guanidine group, a halogen atom (For example, chlorine, bromine, iodine, fluorine), mercapto group, cyano group, carboxy group, phosphate group, sulfo group, hydroxy group, 1 to 10 carbon atoms, preferably 2 to 8 carbon atoms, more preferably 2 carbon atoms To carbamoyl groups (for example, methylcarbamoyl, ethylcarbamoyl, morpholinocarbonyl), sulfamoyl groups having 0 to 10, preferably 2 to 8, and more preferably 2 to 5 carbon atoms (for example, methylsulfamoyl, ethyl). Sulfamoyl, piperidinosulfonyl), nitro group, 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, more preferably An alkoxy group having 1 to 8 carbon atoms (for example, methoxy, ethoxy, 2-methoxyethoxy, 2-phenylethoxy), aryloxy having 6 to 20, preferably 6 to 12, more preferably 6 to 10 carbon atoms A group (for example, phenoxy, p-methylphenoxy, p-chlorophenoxy, naphthoxy), an acyl group having 1 to 20, preferably 2 to 12, more preferably 2 to 8 carbon atoms (for example, acetyl, benzoyl, trichloro) Acetyl), an acyloxy group having 1 to 20 carbon atoms, preferably 2 to 12 carbon atoms, more preferably 2 to 8 carbon atoms (eg acetyloxy, benzoyloxy), 1 to 20 carbon atoms, preferably 2 to 12 carbon atoms. More preferably, the acylamino group having 2 to 8 carbon atoms (for example, acetylamino), carbon 1 to 20, preferably 1 to 10 carbon atoms, more preferably a sulfonyl group having 1 to 8 carbon atoms (e.g., methanesulfonyl, ethanesulfonyl, benzenesulfonyl),

A sulfinyl group having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms (for example, methanesulfinyl, ethanesulfinyl, benzenesulfinyl), 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms More preferably a sulfonylamino group having 1 to 8 carbon atoms (for example, methanesulfonylamino, ethanesulfonylamino, benzenesulfonylamino), 0 to 20, preferably 1 to 12, more preferably 1 to 8 carbon atoms. A substituted or unsubstituted amino group (for example, methylamino, dimethylamino, benzylamino, anilino, diphenylamino), an ammonium group having 0 to 15 carbon atoms, preferably 3 to 10 carbon atoms, more preferably 3 to 6 carbon atoms (Eg trimethylammonium, triethylammonium A hydrazino group having 0 to 15 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms (for example, trimethylhydrazino group), 1 to 15 carbon atoms, preferably 1 to 10 carbon atoms, More preferably, it is a ureido group having 1 to 6 carbon atoms (for example, a ureido group, N, N-dimethylureido group), an imide group having 1 to 15 carbon atoms, preferably 1 to 10 carbon atoms, and more preferably 1 to 6 carbon atoms. (For example, a succinimide group), an alkylthio group having 1 to 20 carbon atoms, preferably 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms (for example, methylthio, ethylthio, propylthio), 6 to 20 carbon atoms, preferably a carbon number An arylthio group having 6 to 12, more preferably 6 to 10 carbon atoms (eg phenylthio, p-methylphenylthio, p-chloro) Thiol, 2-pyridylthio, naphthylthio), an alkoxycarbonyl group having 2 to 20 carbon atoms, preferably 2 to 12 carbon atoms, more preferably 2 to 8 carbon atoms (for example, methoxycarbonyl, ethoxycarbonyl, 2-benzyloxycarbonyl), An aryloxycarbonyl group having 6 to 20 carbon atoms, preferably 6 to 12 carbon atoms, more preferably 6 to 10 carbon atoms (eg, phenoxycarbonyl), 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, more preferably An unsubstituted alkyl group having 1 to 5 carbon atoms (eg, methyl, ethyl, propyl, butyl),

A substituted alkyl group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms (for example, hydroxymethyl, trifluoromethyl, benzyl, carboxyethyl, ethoxycarbonylmethyl, acetylaminomethyl, In this case, an unsaturated hydrocarbon group having 2 to 18 carbon atoms, preferably 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms (for example, vinyl group, ethynyl group 1-cyclohexenyl group, benzylidine group, benzylidene group) is also substituted. To be included in the alkyl group}, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, preferably 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms (eg, phenyl, naphthyl, p-carboxyphenyl). P-nitrophenyl, 3,5-dichlorophenyl, p-cyanophenyl, m- Fluorophenyl, p-tolyl), substituted or unsubstituted heterocyclic group having 1 to 20, preferably 2 to 10, more preferably 4 to 6 carbon atoms (eg pyridyl, 5-methylpyridyl, thienyl, furyl) , Morpholino, and tetrahydrofurfuryl).
Further, as described above, it is also possible to take a structure in which a ring is further condensed to a nitrogen-containing heterocycle. Examples of the condensable ring include an aromatic or non-aromatic (aliphatic) hydrocarbon ring or a heterocyclic ring. Specific examples include a benzene ring, a naphthalene ring, an anthracene ring, and a quinoline ring. Can be mentioned. Such a ring is also included in the substituent represented by V.

On the substituent represented by V, V may further be substituted.
Preferred as the substituent V are an alkyl group, aryl group, alkoxy group, halogen atom, aromatic ring condensation, sulfo group, carboxy group, and hydroxy group.

In the formula, Q ¹ represents a group necessary for the compound represented by the general formula (1) to form a methine compound. When the compound represented by the general formula (1) represents a cyanine dye, Q ¹ is a basic nucleus and is synonymous with the nitrogen-containing heterocycle described in Z ¹ above. On the other hand, when the compound represented by the general formula (1) represents a merocyanine dye, Q ¹ represents an acidic nucleus.
The acidic nuclei here refers to, for example, the 4th edition of “The Theory of the Photographic Process” edited by James (The Theory of the Photographic Process), Macmillan Publishing Co., Ltd., 1977, 1982 Defined. Specifically, U.S. Pat. Nos. 3,567,719, 3,575,869, 3,804,634, 3,837,862, 4,002,480, No. 925,777, JP-A-3-167546, and the like. The acidic nucleus is preferred when forming a 5- or 6-membered nitrogen-containing heterocycle consisting of carbon, nitrogen, and chalcogen (typically oxygen, sulfur, selenium, and tellurium) atoms, and includes the following nuclei. 2-pyrazolin-5-one, pyrazolidin-3,5-dione, imidazolin-5-one, hydantoin, 2 or 4-thiohydantoin, 2-iminooxazolidine-4-one, 2-oxazolin-5-one, 2- Thiooxazoline-2,4-dione, isoxazoline-5-one, 2-thiazoline-4-one, thiazolidine-4-one, thiazolidine-2,4-dione, rhodanine, thiazolidine-2,4-dithione, isorhodanthin, Indan-1,3-dione, thiophen-3-one, thiophen-3-one-1, 1-dioxide, indoline-2-one, indoline-3-one, 2-oxoindazolinium, 3-oxoindazoli Nium, 5,7-dioxo-6,7-dihydrothiazolo [3,2-a] pyrimidine, cyclohexane-1,3- Nucleus of dione, 3,4-dihydroisoquinolin-4-one, 1,3-dioxane-4,6-dione, barbituric acid, 2-thiobarbituric acid, chroman-2,4-dione.

R ¹ represents an alkyl group. Specifically, an unsubstituted alkyl group having 1 to 18, preferably 1 to 7, particularly preferably 1 to 4 carbon atoms (for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, hexyl, octyl, dodecyl, octadecyl) ), A substituted alkyl group having 1 to 18, preferably 1 to 7, particularly preferably 1 to 4 carbon atoms {for example, an aralkyl group (for example, benzyl, 2-phenyl), which includes an alkyl group substituted with the aforementioned V as a substituent. Ethyl), unsaturated hydrocarbon group (for example, allyl group), hydroxyalkyl group (for example, 2-hydroxyethyl, 3-hydroxypropyl), carboxyalkyl group (for example, 2-carboxyethyl, 3-carboxypropyl, 4-carboxy) Butyl, carboxymethyl), alkoxyalkyl groups (eg 2- Toxiethyl, 2- (2-methoxyethoxy) ethyl), aryloxyalkyl groups (eg 2-phenoxyethyl, 2- (1-naphthoxy) ethyl), alkoxycarbonylalkyl groups (eg ethoxycarbonylmethyl, 2-benzyloxycarbonylethyl) ), Aryloxycarbonylalkyl group (for example 3-phenoxycarbonylpropyl), acyloxyalkyl group (for example 2-acetyloxyethyl), acylalkyl group (for example 2-acetylethyl), carbamoylalkyl group (for example 2-morpholinocarbonylethyl) Sulfamoylalkyl group (for example, N, N-dimethylsulfamoylmethyl), sulfoalkyl group (for example, 2-sulfoethyl, 3-sulfopropyl, 3-sulfobutyl, 4-sulfobutyl, 2- [3- Rufopropoxy] ethyl, 2-hydroxy-3-sulfopropyl, 3-sulfopropoxyethoxyethyl), sulfoalkenyl group, sulfatoalkyl group (for example, 2-sulfatoethyl group, 3-sulfatopropyl, 4-sulfatobutyl) ), A heterocyclic-substituted alkyl group (for example, 2- (pyrrolidin-2-one-1-yl) ethyl, tetrahydrofurfuryl),

An alkylsulfonylcarbamoylalkyl group (for example, methanesulfonylcarbamoylmethyl group), an acylcarbamoylalkyl group (for example, acetylcarbamoylmethyl group), an acylsulfamoylalkyl group (for example, acetylsulfamoylmethyl group), an alkylsulfonylsulfamoylalkyl group ( For example, a methanesulfonylsulfamoylmethyl group)}, an unsubstituted aryl group having 6 to 20 carbon atoms, preferably 6 to 10 carbon atoms, more preferably 6 to 8 carbon atoms (for example, a phenyl group, 1-naphthyl group), carbon A substituted aryl group having 6 to 20 carbon atoms, preferably 6 to 10 carbon atoms, more preferably 6 to 8 carbon atoms (for example, an aryl group substituted with V described above as an example of a substituent group). p-methoxyphenyl group, p-methyl An unsubstituted heterocyclic group having 1 to 20 carbon atoms, preferably 3 to 10 carbon atoms, and more preferably 4 to 8 carbon atoms (for example, a 2-furyl group, 2), and the like. -Thienyl group, 2-pyridyl group, 3-pyrazolyl, 3-isoxazolyl, 3-isothiazolyl, 2-imidazolyl, 2-oxazolyl, 2-thiazolyl, 2-pyridazyl, 2-pyrimidyl, 3-pyrazyl, 2- (1, 3,5-triazolyl), 3- (1,2,4-triazolyl), 5-tetrazolyl), substituted heterocycle having 1 to 20, preferably 3 to 10, more preferably 4 to 8 carbon atoms A group (for example, a heterocyclic group substituted with V described above as an example of the substituent. Specific examples include a 5-methyl-2-thienyl group, a 4-methoxy-2-pyridyl group, and the like. That.), And the like.

R ¹ is preferably a sulfoalkyl group, a carboxyalkyl group, or an unsubstituted alkyl group.

L ¹ and L ² each independently represent a methine group. The methine group represented by L ¹ and L ² may have a substituent, and examples of the substituent include those exemplified in the above-mentioned V.
For example, a substituted or unsubstituted alkyl group having 1 to 15 carbon atoms, preferably 1 to 10 carbon atoms, particularly preferably 1 to 5 carbon atoms (for example, methyl, ethyl, 2-carboxyethyl), substituted or unsubstituted An aryl group having 6 to 20 carbon atoms, preferably 6 to 15 carbon atoms, more preferably 6 to 10 carbon atoms (eg, phenyl, o-carboxyphenyl), substituted or unsubstituted carbon atoms having 3 to 20 carbon atoms, preferably 4 to 15, more preferably a heterocyclic group having 6 to 10 carbon atoms (for example, N, N-dimethylbarbituric acid group), halogen atom (for example, chlorine, bromine, iodine, fluorine), 1 to 15 carbon atoms, preferably Is an alkoxy group having 1 to 10 carbon atoms, more preferably 1 to 5 carbon atoms (for example, methoxy, ethoxy), 0 to 15 carbon atoms, preferably 2 to carbon atoms. 0, more preferably an amino group having 4 to 10 carbon atoms (for example, methylamino, N, N-dimethylamino, N-methyl-N-phenylamino, N-methylpiperazino), 1 to 15 carbon atoms, preferably 1 carbon atom To 10, more preferably an alkylthio group having 1 to 5 carbon atoms (for example, methylthio, ethylthio), an arylthio group having 6 to 20, preferably 6 to 12, and more preferably 6 to 10 carbon atoms (for example, phenylthio, p-methylphenylthio) and the like. Further, it may form a ring with another methine group, or may be bonded to Z ¹ or R ¹ to form a ring.

L ¹ and L ² are preferably unsubstituted methine groups.
p ¹ represents 0 or 1. Preferably it is 0.

M ¹ is included in the formula to indicate the presence of a cation or anion when necessary to neutralize the ionic charge of the dye. Typical cations include inorganic cations such as hydrogen ions (H ⁺ ), alkali metal ions (eg, sodium ions, potassium ions, lithium ions), alkaline earth metal ions (eg, calcium ions), ammonium ions (eg, Organic ions such as ammonium ion, tetraalkylammonium ion, pyridinium ion, ethylpyridinium ion). The anion may be either an inorganic anion or an organic anion, such as a halogen anion (for example, fluorine ion, chlorine ion, iodine ion), a substituted aryl sulfonate ion (for example, p-toluenesulfonate ion, p- Chlorobenzenesulfonate ion), aryl disulfonate ion (for example, 1,3-benzenesulfonate ion, 1,5-naphthalenedisulfonate ion, 2,6-naphthalenedisulfonate ion), alkyl sulfate ion (for example, methyl sulfate ion) ), Sulfate ion, thiocyanate ion, perchlorate ion, tetrafluoroborate ion, picrate ion, acetate ion, trifluoromethanesulfonate ion. Furthermore, you may use the ionic polymer or the other pigment | dye which has a charge opposite to a pigment | dye. CO ₂ ⁻ and SO ₃ ⁻ can also be expressed as CO ₂ H and SO ₃ H when they have hydrogen ions as counter ions.

m ¹ represents a number of 0 or more necessary for balancing electric charges, preferably a number of 0 to 4, more preferably a number of 0 to 1, and 0 when a salt is formed in the molecule. It is.

  Next, specific examples of the polymethine compound, which is a dye suitably used for forming the dye aggregate in the present invention, are shown below, but the present invention is not limited thereto.

  The polymethine compound that can be suitably used in the present invention can be synthesized by a known method. The synthesis of polymethine compounds can be carried out with reference to the method described in “Cyanine Dyes and Related Compounds” (Hamer, John & Willey New York, 1964).

(Dye aggregate and method for forming the same)
Next, the dye aggregate according to the present invention will be described. The dye aggregate used in the nonlinear optical material of the present invention can be formed by mixing the dye and an ionic liquid. At this time, the said pigment | dye may be used independently and may use a some pigment | dye together.
Further, the mixing ratio of the dye and the ionic liquid disposed on the support is not particularly limited, but the molar ratio is preferably dye: ionic liquid = 1: 0.01 to 1: 1000, and 1: 1 to 1: 100 is more preferable, and 1: 2-1: 50 is still more preferable.
In the present invention, a nonlinear optical material is obtained by disposing this mixed solution on a substrate. As described above, since the ionic liquid has low volatility, when a layer made of the mixed liquid is formed on the support, the stable change of the liquid due to the volatilization of the liquid is formed. However, depending on conditions, for example, when the amount of the ionic liquid with respect to the dye aggregate is excessive, the fluidity of the layer becomes high. In such a case, in order to stabilize the coating liquid layer, Means such as adding a compound having a thickening action can also be used. Examples of such compounds include gelling agents.

  As the ionic liquid used for forming the dye aggregate, only one kind may be used, or a mixture of two or more kinds of ionic liquids may be used. Moreover, when mixing with a pigment | dye, only 1 or more types of ionic liquids may be used, and solvents other than an ionic liquid may be used together according to the objective. The solvent that can be used in combination here may be any solvent, but is preferably a polar solvent, such as water, alcohols such as methanol, amides such as dimethylformamide, and sulfoxides such as dimethyl sulfoxide. The added solvent may be a combination of two or more.

Further, when forming the dye aggregate, an additive may be used in combination for the purpose of promoting the association. As the additive, inorganic salt compounds and organic salt compounds are preferable. Particularly preferred are inorganic salt compounds such as potassium iodide, sodium iodide, potassium bromide, sodium bromide and the like.
The addition amount of the additive for promoting such association is not particularly limited, but is preferably in a molar ratio of additive: ionic liquid = 1: 1 to 1: 1000, particularly preferably The range is from 1: 5 to 1: 100, more preferably from 1:10 to 1:50.

  The dye aggregate used in the nonlinear optical material of the present invention preferably gives a larger transition moment. From such a viewpoint, a J-aggregate in which the dyes are associated linearly is preferable. The number of molecules of the dye constituting the aggregate may be any, but it is preferably a dye aggregate of 10 to 1000 molecules, particularly preferably 20 to 100 molecules.

In forming the dye aggregate, the temperature condition in the case of mixing the dye and the ionic liquid is not particularly limited, but is preferably in the range of 0 ° C. to 300 ° C. from the viewpoint of promoting association formation. Particularly preferably, it is in the range of 10 ° C to 100 ° C.
Moreover, there is no restriction | limiting in particular also about the time to form a pigment | dye aggregate, Preferably it is 10 minutes-1000 hours, Most preferably, it is 30 minutes-500 hours.

The nonlinear optical material of the present invention has an oriented dye aggregate and an ionic liquid on a substrate. In forming the nonlinear optical material, the dye and the ionic liquid are mixed, and the ionic liquid is mixed according to the above conditions. After the dye aggregate is formed in the liquid, the mixture may be applied and placed on the substrate.
The arrangement on the substrate may be performed after the dye aggregate is formed, or the dye and the ionic liquid are mixed and then applied onto the substrate, and after the application, the dye aggregate is formed in the ionic liquid. May be.

There is no particular limitation on the method for applying the mixed solution on the substrate, and a known application method can be arbitrarily selected. From the viewpoint of forming a uniform coating film, roll coating, spin coating, printing method ( For example, it is preferable to take a method such as screen printing or silk printing.
The coating amount of the mixed solution on the substrate is appropriately selected according to the purpose, but from the viewpoint that the absorption of the dye aggregate becomes a suitable value as the nonlinear optical material, 1.0 g / m ^{2 to} 1000 g / It is preferably about m ² .

In order to form the nonlinear optical material of the present invention, it is preferable to orient the dye aggregate formed on the substrate and formed in the ionic liquid. Any means for orienting the dye aggregate may be used, and examples include shear orientation, a method using an alignment film subjected to rubbing treatment, orientation by a magnetic field, orientation by an electric field, orientation by light, and the like. A method using an alignment film subjected to alignment or rubbing treatment, and a method using an alignment film subjected to rubbing treatment is particularly preferable. The alignment film may be any film, but is preferably a polyimide film.
More specifically, it is preferable to adopt a method in which the substrate surface is oriented by rubbing treatment, and then the ionic liquid and the dye aggregate are disposed on the oriented substrate. At this time, the substrate surface may be rubbed and aligned, or another alignment film may be disposed on the substrate surface.
The orientation of the dye aggregate in the ionic liquid can be confirmed by observing with a polarizing microscope. That is, when the dye aggregate is oriented, it exhibits strong dichroism. That is, a dye aggregate that has strong absorption only in one linearly polarized light when measuring each absorption spectrum with linearly polarized light orthogonal to each other is preferable.

  In the present invention, it is preferable to use a J-aggregate as the dye aggregate. That is, since the dye molecules in the J-aggregate are linearly aligned (usually 50 to 100 molecules), the alignment of the aligned dye aggregate is relaxed by the thermal energy of the normal monomer. On the other hand, it is because it has the characteristic that orientation relaxation is small.

  In the present invention, oriented dye aggregates present in an ionic liquid, particularly J-aggregates having a linear structure, have a very strong transition dipole moment and a large polarizability in the long axis direction of the aggregate. When this linear dye aggregate is aligned in the same direction by an alignment treatment, for example, a rubbing treatment, large second-order and third-order nonlinear optical constants are given. Further, since this dye aggregate gives a large refractive index change in light absorption, it becomes possible to modulate signal light by the refractive index change induced by light. Furthermore, by arranging the dye aggregate in an ionic liquid having a high dielectric constant, the size of the aggregate increases, the change in the polarizability and the refractive index is large, and the nonlinearity is excellent.

  The nonlinear optical material of the present invention can be provided with a protective film as necessary, but it is preferable to provide a protective film from the viewpoint of stability. There is no restriction | limiting in particular in the thickness of such a protective film, As a protective film, a glass substrate, a plastic substrate, a metal substrate (metal thin film etc.) etc. are mentioned, for example.

  The nonlinear optical material of the present invention obtained as described above may be operated at any temperature, but is preferably in the range of 0 ° C to 100 ° C, particularly preferably in the range of 10 ° C to 50 ° C. is there.

  The oriented dye aggregate in the present invention can be suitably used for a nonlinear optical material having any structure. For example, the elements described in Toshio Fukumi, “New edition optical material handbook”, Realize, 2000, and the like can be mentioned. Specifically, an optical switch, an optical car shutter switch, an optical distributor, an optical modulator, and the like.

  Hereinafter, an example of an element will be described by applying the nonlinear optical material of the present invention. FIG. 2 is a model diagram showing an embodiment of the configuration of the optical switch 20 using the nonlinear optical material of the present invention. The optical switch 20 reflects a layer 26 containing an aligned dye aggregate and an ionic liquid on a support in which a reflecting plate 22 and an alignment film 24 are disposed on a substrate 12, and further reflects the surface of the layer 26. It is composed of a laminated body of gold thin films 28 arranged for the purpose. As shown in FIG. 2, the nonlinear optical material of the present invention functions as an optical switch by irradiating control light perpendicularly to the surface of the optical switch and converting the signal light incident at a predetermined angle by the optical switch 20. To do.

  FIG. 3 is a model diagram showing a configuration example in which the nonlinear optical material of the present invention is applied to the optical Kerr shutter switch 30. The probe light passes through the polarizer 32 and the mirror 34 and enters the layer 36 containing the aligned dye aggregate and the ionic liquid. The mirror 34 is also irradiated with gate light on the surface facing the incident direction of the probe light. The probe light that has passed through the layer 36 containing the dye aggregate and the ionic liquid is output through a filter 38 and an analyzer 40.

  The optical elements exemplified above are merely examples of application of the nonlinear optical material of the present invention, and the nonlinear optical material of the present invention can be suitably applied to various optical elements due to its excellent nonlinearity.

  The present invention will be described more specifically with reference to the following examples. The materials, reagents, amounts and ratios, operations, etc. shown in the following examples can be appropriately changed without departing from the gist of the present invention. Therefore, the scope of the present invention is not limited to the following specific examples. .

(Example 1)
Using 1 g of ethylmethylimidazolium tetrafluoroborate as the ionic liquid, 0.1 g of cyanine dye (1-1) and 0.2 g of sodium iodide are added thereto, and the mixture is allowed to stand at room temperature for 1 hour to prepare a coating solution. did. A non-linear optical material was formed by applying the coating solution on a glass substrate with a polyimide alignment film subjected to rubbing treatment (SE1211, manufactured by Nissan Chemical Co., Ltd.) by spin coating so that the coating amount was 10 g / m ² . .
When the absorption spectrum of the optical material was measured, a peak having a maximum maximum wavelength at 590 nm based on the J-aggregate of cyanine dye (1-1) shifted by a longer wavelength than the dye monomer was given. When observed with a polarizing microscope, the dye aggregate showed strong dichroism. This means that the dye aggregate formed in the ionic liquid is aligned on the rubbed polyimide alignment film. Further, it was confirmed by fluorescence spectrum measurement that the peak gave strong fluorescence, and it was found that the obtained optical material had excellent nonlinearity.
Furthermore, even when this optical material is left in the air in an open system for one week, the solvent does not evaporate from the coating liquid layer containing the dye aggregate and the ionic liquid, and the J-aggregate of the dye is stable. It was confirmed to exist.

(Example 2)
Using 1 g of ethylmethylimidazolium tetrafluoroborate as an ionic liquid, 0.1 g of cyanine dye (1-13) and 0.2 g of sodium iodide are added to the liquid, and the mixture is allowed to stand at room temperature for 3 days. Adjusted. A non-linear optical material is formed by applying the coating solution by spin coating on a glass with a polyimide alignment film subjected to the same rubbing treatment as used in Example 1 so that the coating amount becomes 10 g / m ^2. did.
When the absorption spectrum of the optical material was measured, a peak having a maximum maximum wavelength at 550 nm based on a J-aggregate of cyanine dye (1-13) shifted by a longer wavelength than the monomer was given. When observed with a polarizing microscope, the dye aggregate showed strong dichroism. This means that the formed dye aggregate is aligned on the rubbed polyimide alignment film. Further, it was confirmed by fluorescence spectrum measurement that the peak gave strong fluorescence, and it was found that the obtained optical material had excellent nonlinearity.
Furthermore, even when this optical material is left in the air in an open system for one week, the solvent does not evaporate from the coating liquid layer containing the dye aggregate and the ionic liquid, and the J-aggregate of the dye is stable. It was confirmed to exist.

(Comparative Example 1)
Cyanine Dye (1-13) A 2% by weight PVA methanol aqueous solution of cyanine dye (1-13) was prepared by mixing 0.1 g of a methanol solution and an aqueous PVA solution. A non-linear optical material was obtained by forming an aligned dye aggregate on a glass with a polyimide alignment film by the same method.
When the absorption spectrum of the optical material was measured, a peak based on the J-aggregate of cyanine dye (1-13) was observed 10 minutes after coating, but the peak decreased after 1 day. all right. This is because the dye aggregate was precipitated by the volatilization of the solvent, and it was confirmed that the stability over time was low.

It is a model figure showing the one aspect | mode of the nonlinear optical material of this invention. It is a model figure which shows the one aspect | mode of the structure of the optical switch using the nonlinear optical material of this invention. It is a model figure which shows the one aspect | mode of the structure of the optical Kerr shutter switch using the nonlinear optical material of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Nonlinear optical material 12 Substrate 14 Ionic liquid 16 Dye aggregate 20 Optical switch 26 Layer 30 containing dye aggregate and ionic liquid Optical Kerr shutter switch

Claims (7)

  A composition comprising a dye aggregate and an ionic liquid.   The composition according to claim 1, wherein the dye aggregate is a J-aggregate.   The composition according to claim 1 or 2, wherein the dye in the dye aggregate is at least one selected from a cyanine dye, a merocyanine dye, and an oxonol dye.   The composition according to any one of claims 1 to 3, wherein the ionic liquid has an imidazolium salt compound or an iodonium ion as a counter ion.   A nonlinear optical material comprising the composition according to any one of claims 1 to 4 on a substrate.   6. The nonlinear optical material according to claim 5, wherein the dye aggregate is provided on a substrate oriented by rubbing.   The nonlinear optical material according to claim 5 or 6, wherein the dye aggregate is linearly oriented on a substrate.

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