JP2007119443A - Phorphyrin-azulene condensate and two-photon absorbing material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a two-photon absorbing material using a phorphyrin monomer having a high two-photon absorbing cross section. <P>SOLUTION: The phorphyrin-azulene condensate is represented by general formula (1) (wherein P is a phorphyrin ring which may have a substituent; L are each 0-20C conjugated chain linking group; A are each an azulene ring substituent which may have a substituent; n is an integer of 1-12, wherein when n is ≥2, each L and A may be same or different). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a novel porphyrin-azulene condensate useful as a porphyrin-based dye used in a two-photon absorbing material and a two-photon absorbing material containing the porphyrin-azulene condensate.

  In recent years, among the nonlinear optical characteristics of organic compounds, the multiphoton absorption phenomenon has attracted attention. Multiphoton absorption is a phenomenon in which a compound absorbs several photons and transitions from a ground state to an excited state. In particular, in the two-photon absorption phenomenon, excitation can be performed by applying two photons to one molecule using light having a wavelength about twice the one-photon excitation wavelength. The probability that two photons hit one molecule at a time is proportional to the square of the photon density, and as the laser beam is focused on the sample, the photon density is proportional to the square of the distance as it moves away from the focal plane. Decrease. Therefore, the probability that two-photon absorption will occur decreases in proportion to the fourth power of the distance as the distance from the focal plane increases. Utilizing this phenomenon, application of two-photon absorption is expected in the fields of optical memory, two-photon modeling, two-photon photodynamic therapy, and the like. In addition, two-photon emission that emits light in a radiation deactivation process from an excited state that has been absorbed by two photons can extract light having a wavelength shorter than the wavelength of the incident light (= light with high energy). As well as research.

  Conventionally known compounds having two-photon absorption characteristics include compounds represented by the following structural formula (A-1), porphyrin derivatives described in Non-Patent Document 1, and the like.

  By the way, there is a two-photon absorption cross section as an index of the two-photon absorption characteristic, and it can be said that the higher the value, the better the two-photon absorption characteristic. In general, one of the compounds currently expected as a compound having a large two-photon absorption cross section is a porphyrin-based compound. The reason why the compound is expected as a two-photon absorption material is that it has a large aromatic ring of 18π electron system.

  However, for example, a two-photon absorption material using a porphyrin derivative described in Patent Document 1 has only a two-photon absorption cross section of about 2,000 GM, and this value is insufficient for application to an optical memory or the like. . There is also an approach to increase the two-photon absorption cross section by increasing the amount of porphyrin. Currently, those described in Non-Patent Document 2, Non-Patent Document 3 and the like have been proposed, but these compounds are produced by the increase in the amount. For reasons of increased molecular weight and increased planarity, it is easily expected that the solubility in a solvent is poor and difficult to use. In addition, since the molecular weight increases dramatically due to the increase in quantity, even if the apparent two-photon absorption cross-section is high, only a small amount can be used when actually used, and there is a concern that the real two-photon absorption characteristics may be lowered. . Further, since the increase in the number greatly increases the π-conjugated system, absorption in a wide wavelength region is caused, and the one-photon absorption effect cannot be ignored. For example, since the porphyrin dimer (A-2) having the following structure has a wide absorption from ultraviolet to near infrared, it has a high two-photon absorption cross section of 10,000 GM or more in the two-photon absorption cross-section measurement by the Z-scan method. However, it is difficult to use as a two-photon absorption material. In fact, as a result of investigations by the present inventors, it has become clear that the one-photon absorption effect cannot be removed in the two-photon absorption cross-section measurement by the pump-probe method.

For these reasons, it has been desired to develop a two-photon absorption material using a porphyrin monomer having a large two-photon absorption cross-section and capable of removing the one-photon absorption effect.
Japanese Patent Laid-Open No. 2001-354673 J. et al. Am. Chem. Soc. , 2003 (125 volumes), p. 13356 J. et al. Phys. Lett. A, 2005 (Vol. 109), 2996-2999. J. et al. Am. Chem. Soc. 2005 (127), 534-535

  The present invention has been made in view of the above-described conventional situation, and an object of the present invention is to provide a two-photon absorption material using a porphyrin monomer having a high two-photon absorption cross-sectional area.

As a result of intensive studies, the present inventors have found that a novel porphyrin monomer in which an azulene ring substituent is bonded to a porphyrin ring via a conjugated chain linking group exhibits excellent two-photon absorption characteristics. Completed.
That is, the gist of the present invention is as follows.

（式（１）中、Ｐは置換基を有していてもよいポルフィリン環を表し、Ｌは炭素数０〜２０の共役鎖状連結基を表し、Ａは置換基を有していても良いアズレン環置換基を表し、ｎは１〜１２の整数を表す。なお、ｎが２以上の場合、それぞれのＬおよびＡは互いに同じでも、異なっていても良い。） [1] A porphyrin-azulene condensate represented by the following general formula (1).

(In formula (1), P represents a porphyrin ring which may have a substituent, L represents a conjugated chain linking group having 0 to 20 carbon atoms, and A may have a substituent. Represents an azulene ring substituent, and n represents an integer of 1 to 12. When n is 2 or more, each L and A may be the same or different.

（式（２）中、Ｐは置換基を有していてもよいポルフィリン環を表し、Ａは置換基を有していても良いアズレン環置換基を表し、ｍは１〜１０の整数を表し、ｎは１〜１２の整数を表す。なお、ｎが２以上の場合、それぞれのｍおよびＡは互いに同じでも、異なっていても良い。） [2] A porphyrin-azulene condensate represented by the following general formula (2) in [1].

(In the formula (2), P represents an optionally substituted porphyrin ring, A represents an optionally substituted azulene ring substituent, and m represents an integer of 1 to 10. , N represents an integer of 1 to 12. When n is 2 or more, m and A may be the same or different.

（式（３）中、Ｒ^１〜Ｒ^１０はそれぞれ独立に水素原子、置換基を有していても良い芳香環置換基、または炭素数０〜２０の非芳香環置換基を表し、Ｌ^１およびＬ^２はそれぞれ独立に炭素数０〜２０の共役鎖状連結基を表し、Ａ^１およびＡ^２はそれぞれ独立に置換基を有していても良いアズレン環置換基を表し、Ｍ^１は２個の水素原子もしくは２価以上の金属イオンを表す。なお、Ｍ^１が３価以上の金属イオンである場合、さらに炭素数０〜２０のカウンターアニオンを有していても良い。） [3] A porphyrin-azulene condensate represented by the following general formula (3) in [1].

(Expressed in the formula (3), R ¹ ~R ¹⁰ independently represents a hydrogen atom, which may have a substituent aromatic ring substituent, or a non-aromatic ring substituents 0 to 20 carbon atoms, L ¹ And L ² each independently represents a conjugated chain linking group having 0 to 20 carbon atoms, A ¹ and A ² each independently represent an azulene ring substituent which may have a substituent, and M ¹ represents 2 Represents a hydrogen atom or a metal ion having a valence of 2 or more, and when M ¹ is a metal ion having a valence of 3 or more, it may further have a counter anion having 0 to 20 carbon atoms.)

（式（４）中、Ｒ^１１〜Ｒ^２０はそれぞれ独立に水素原子、置換基を有していても良い芳香環置換基、または炭素数０〜２０の非芳香環置換基を表し、Ａ^３およびＡ^４はそれぞれ独立に置換基を有していても良いアズレン環置換基を表し、Ｍ^２は２個の水素原子もしくは２価以上の金属イオンを表し、ｐおよびｑはそれぞれ独立に１〜１２の整数を表す。なお、Ｍ^２が３価以上の金属イオンである場合、さらに炭素数０〜２０のカウンターアニオンを有していても良い。） [4] A porphyrin-azulene condensate represented by the following general formula (4) in [3].

(Expressed in the formula ^{(4), R} 11 ~R ²⁰ each independently represent a hydrogen atom, which may have a substituent aromatic ring substituent, or a non-aromatic ring substituents 0 to 20 carbon atoms, ^{A 3} And A ⁴ each independently represents an optionally substituted azulene ring substituent, M ² represents two hydrogen atoms or a divalent or higher metal ion, and p and q each independently represent 1 to It represents an integer of 12. In addition, when M ² is a trivalent or higher metal ion, it may further have a counter anion having 0 to 20 carbon atoms.

[5] A two-photon absorption material comprising the porphyrin-azulene condensate according to any one of [1] to [4].

  The porphyrin-azulene condensate of the present invention represented by the general formula (1) exhibits a high two-photon absorption cross section and is a relatively low molecular weight porphyrin monomer. Is expected to provide a high-performance two-photon absorption material.

  One of the reasons why the porphyrin-azulene condensate of the present invention has a high two-photon absorption cross-section is presumed to be that a donor-acceptor effect was born by conjugating the porphyrin ring and the azulene ring.

  Embodiments of the present invention will be specifically described below, but the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist of the present invention.

[Porphyrin-azulene condensate]
The porphyrin-azulene condensate of the present invention is represented by the following general formula (1), preferably, in the general formula (1), wherein L is an ethynylene group or an oligoethynylene group, or the following general formula (1) The following general formula (3) in which the substitution position of L is the meso position of the porphyrin ring, particularly preferably, in the general formula (3), L ¹ and L ² are an ethynylene group or an oligoethynylene group. And a porphyrin monomer compound in which an azulene ring is bonded to a porphyrin ring via a conjugated chain linking group.

（式（１）中、Ｐは置換基を有していてもよいポルフィリン環を表し、Ｌは炭素数０〜２０の共役鎖状連結基を表し、Ａは置換基を有していても良いアズレン環置換基を表し、ｎは１〜１２の整数を表す。なお、ｎが２以上の場合、それぞれのＬおよびＡは互いに同じでも、異なっていても良い。）

(In formula (1), P represents a porphyrin ring which may have a substituent, L represents a conjugated chain linking group having 0 to 20 carbon atoms, and A may have a substituent. Represents an azulene ring substituent, and n represents an integer of 1 to 12. When n is 2 or more, each L and A may be the same or different.

（式（２）中、Ｐは置換基を有していてもよいポルフィリン環を表し、Ａは置換基を有していても良いアズレン環置換基を表し、ｍは１〜１０の整数を表し、ｎは１〜１２の整数を表す。なお、ｎが２以上の場合、それぞれのｍおよびＡは互いに同じでも、異なっていても良い。）

(In the formula (2), P represents an optionally substituted porphyrin ring, A represents an optionally substituted azulene ring substituent, and m represents an integer of 1 to 10. , N represents an integer of 1 to 12. When n is 2 or more, m and A may be the same or different.

（式（３）中、Ｒ^１〜Ｒ^１０はそれぞれ独立に水素原子、置換基を有していても良い芳香環置換基、または炭素数０〜２０の非芳香環置換基を表し、Ｌ^１およびＬ^２はそれぞれ独立に炭素数０〜２０の共役鎖状連結基を表し、Ａ^１およびＡ^２はそれぞれ独立に置換基を有していても良いアズレン環置換基を表し、Ｍ^１は２個の水素原子もしくは２価以上の金属イオンを表す。なお、Ｍ^１が３価以上の金属イオンである場合、さらに炭素数０〜２０のカウンターアニオンを有していても良い。）

(Expressed in the formula (3), R ¹ ~R ¹⁰ independently represents a hydrogen atom, which may have a substituent aromatic ring substituent, or a non-aromatic ring substituents 0 to 20 carbon atoms, L ¹ And L ² each independently represents a conjugated chain linking group having 0 to 20 carbon atoms, A ¹ and A ² each independently represent an azulene ring substituent which may have a substituent, and M ¹ represents 2 Represents a hydrogen atom or a metal ion having a valence of 2 or more, and when M ¹ is a metal ion having a valence of 3 or more, it may further have a counter anion having 0 to 20 carbon atoms.)

（式（４）中、Ｒ^１１〜Ｒ^２０はそれぞれ独立に水素原子、置換基を有していても良い芳香環置換基、または炭素数０〜２０の非芳香環置換基を表し、Ａ^３およびＡ^４はそれぞれ独立に置換基を有していても良いアズレン環置換基を表し、Ｍ^２は２個の水素原子もしくは２価以上の金属イオンを表し、ｐおよびｑはそれぞれ独立に１〜１２の整数を表す。なお、Ｍ^２が３価以上の金属イオンである場合、さらに炭素数０〜２０のカウンターアニオンを有していても良い。）

(Expressed in the formula ^{(4), R} 11 ~R ²⁰ each independently represent a hydrogen atom, which may have a substituent aromatic ring substituent, or a non-aromatic ring substituents 0 to 20 carbon atoms, ^{A 3} And A ⁴ each independently represents an optionally substituted azulene ring substituent, M ² represents two hydrogen atoms or a divalent or higher metal ion, and p and q each independently represent 1 to It represents an integer of 12. In addition, when M ² is a trivalent or higher metal ion, it may further have a counter anion having 0 to 20 carbon atoms.

  The porphyrin-azulene condensate of the present invention represented by the general formula (1) will be described below.

{Explanation of words}
In the present invention, an “aromatic ring” means a ring having aromaticity, that is, a ring having a (4r + 2) π electron system (r is a natural number), and therefore, “aromatic hydrocarbon ring” and “aromatic heterocycle”. Ring ". “Hydrocarbon ring” means both “aromatic hydrocarbon ring” and “non-aromatic hydrocarbon ring”, and “heterocycle” means “aromatic heterocycle” and “non-aromatic heterocycle”. "Ring" means both. The skeleton structure of an aromatic ring is usually a 5- or 6-membered monocyclic ring or a 2-6 condensed ring. The aromatic ring includes an aromatic hydrocarbon ring, an aromatic heterocyclic ring, an anthracene ring, and a carbazole. A condensed ring such as a ring or an azulene ring is also included. “... Ring substituent” such as “aromatic ring substituent” is a monovalent substituent obtained by removing one hydrogen atom from such a ring such as an aromatic ring. Therefore, “azulene ring substituent” refers to a monovalent substituent obtained by removing one hydrogen atom from an azulene ring. Further, the “non-aromatic ring substituent” refers to a substituent other than the aromatic ring substituent.

  “(Hetero) aryl” means both “aryl” and “heteroaryl”, and “(hetero) aralkyl” means both “aralkyl” and “heteroaralkyl”.

  In the present invention, “may have a substituent” means that one or more substituents may be present.

{Porphyrin ring: P}
<Porphyrin ring: Structure of P>
In general formula (1), (2), P represents the porphyrin ring which may have a substituent (substituents other than (LA) _n ).

The substituent in this case is not particularly limited, but is represented by R ^{1 to} R ¹⁰ and R ^{11 to} R ²⁰ in the general formulas (3) and (4), and an aromatic ring substituent having 20 or less carbon atoms, Any of non-aromatic ring substituents having 0 to 20 carbon atoms may be mentioned. In addition, when this substituent is an aromatic ring substituent, the hydrogen atom on the aromatic ring may be further substituted with an arbitrary substituent having 20 or less carbon atoms.
Specific examples of these substituents are shown below.

<Porphyrin ring: Aromatic ring substituent introduced into P>
(Skeleton structure of aromatic ring substituents)
Specific examples of the skeleton structure of the aromatic ring substituent include a 5-membered monocyclic ring as a furan ring, a thiophene ring, a pyrrole ring, an imidazole ring, a thiazole ring, an oxadiazole ring, a 6-membered monocyclic ring as a benzene ring and a pyridine ring. And pyrazine ring and condensed ring include naphthalene ring, phenanthrene ring, azulene ring substituent, pyrene ring, quinoline ring, isoquinoline ring, quinoxaline ring, benzofuran ring, carbazole ring, dibenzothiophene ring, anthracene ring and the like. Of these, a monocyclic ring is preferred for reasons of synthesis, a 6-membered monocyclic ring is more preferred, and a benzene ring is particularly preferred.

(Substituent which the aromatic ring substituent may have)
In the aromatic ring substituent, a hydrogen atom on the aromatic ring may be further substituted with an arbitrary substituent.
Examples of the substituent that the aromatic ring substituent has include an alkyl group, an alkenyl group, an alkynyl group, a hydrocarbon ring group, a heterocyclic group, an alkoxy group, an alkylcarbonyl group, a (hetero) aryloxy group, a (hetero) aralkyloxy group, Furthermore, an amino group, a nitro group, a cyano group, an ester group, a halogen atom, a hydroxyl group and the like which may have a substituent are exemplified. Preferably, it is an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, a hydrocarbon ring group having 3 to 20 carbon atoms, a 5- or 6-membered monocyclic ring, or A heterocyclic group derived from a 2-6 condensed ring, an alkoxy group having 1 to 9 carbon atoms, an alkylcarbonyl group having 2 to 18 carbon atoms, a (hetero) aryloxy group having 2 to 18 carbon atoms, a 3 to 18 carbon atoms ( Hetero) aralkyloxy group, amino group, alkylamino group having 2 to 20 carbon atoms, (hetero) arylamino group having 2 to 20 carbon atoms, nitro group, cyano group, ester group having 2 to 6 carbon atoms, halogen atom, Such as a hydroxyl group.

  Examples of the alkyl group having 1 to 20 carbon atoms include methyl group, ethyl group, propyl group, isopropyl group, butyl group, iso-butyl group, sec-butyl group, tert-butyl group, hexyl group, octyl group, hexa And dodecyl group.

  Examples of the alkenyl group having 2 to 20 carbon atoms include a vinyl group, a propenyl group, a butenyl group, a 2-methyl-1-propenyl group, a hexenyl group, an octenyl group, and a hexadodecenyl group.

  Examples of the alkynyl group having 2 to 20 carbon atoms include ethynyl group, propynyl group, butynyl group, 2-methyl-1-propynyl group, hexynyl group, octynyl, hexadodecynyl group and the like.

  Examples of the hydrocarbon ring group having 3 to 20 carbon atoms include a cyclopropyl group, a cyclohexyl group, a cyclohexenyl group, a tetradecahydroanthranyl group, a phenyl group, an anthranyl group, a phenanthryl group, and a ferrocenyl group.

  Examples of 5- or 6-membered monocyclic or heterocyclic groups derived from 2 to 6 condensed rings include pyridyl, thienyl, benzothienyl, carbazolyl, quinolinyl, 2-piperidinyl, 2-piperazinyl, An octahydroquinolinyl group etc. are mentioned.

  Examples of the alkoxy group having 1 to 9 carbon atoms include methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, iso-butoxy group, sec-butoxy group, tert-butoxy group, hexyloxy group, octyloxy Group and the like.

  Examples of the alkylcarbonyl group having 2 to 18 carbon atoms include a methylcarbonyl group, an ethylcarbonyl group, an isopropylcarbonyl group, a tert-butylcarbonyl group, a cyclohexylcarbonyl group, and a hexadodecylcarbonyl group.

  Examples of the (hetero) aryloxy group having 2 to 18 carbon atoms include aryloxy groups such as phenoxy group, naphthyloxy group, pyrenyloxy group, 2-thienyloxy group, 2-furyloxy group, 2-quinolyloxy group, etc. And the heteroaryloxy group.

  Examples of the (hetero) aralkyloxy group having 3 to 18 carbon atoms include aralkyloxy groups such as benzyloxy group, phenethyloxy group, naphthylmethoxy group, pyrenylmethoxy group, 2-thienylmethoxy group, 2-furylmethoxy group, Heteroaralkyloxy groups such as 2-quinolylmethoxy group and the like can be mentioned.

  Examples of the alkylamino group having 2 to 20 carbon atoms include an ethylamino group, a dimethylamino group, a methylethylamino group, a dibutylamino group, a piperidyl group, and a hexadodecylamino group.

  Examples of the (hetero) arylamino group having 2 to 20 carbon atoms include an arylamino group such as a diphenylamino group, a dinaphthylamino group, a naphthylphenylamino group, a ditolylamino group, and a pyrenylamino group, and di (2-thienyl) amino. And heteroarylamino groups such as a group, a di (2-furyl) amino group, and a phenyl (2-thienyl) amino group.

  Examples of the ester group having 2 to 6 carbon atoms include methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group, isopropoxycarbonyl group, tert-butoxycarbonyl group and the like.

  Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

  When the hydrogen atom on the aromatic ring substituent is further substituted with a substituent, the substituents may be bonded to each other to form a cyclic structure. For example, when the aromatic ring substituent is a group derived from a benzene ring, the following structures are exemplified as examples in which substituents of the benzene ring are bonded to each other to form a cyclic structure. In the following, the part a is the bonding position to the porphyrin ring.

  In addition, it is preferable from the surface of the solubility improvement to the solvent of the porphyrin-azulene condensate of this invention that the hydrogen atom on this aromatic ring substituent is further substituted by the substituent.

<Porphyrin ring: non-aromatic ring substituent introduced into P>
When the substituent that the porphyrin ring may have is a non-aromatic ring substituent having 0 to 20 carbon atoms, as specific examples thereof, among the substituents that the above-described aromatic ring substituent may have , Which are non-aromatic ring substituents.

From the viewpoint of the stability of the porphyrin-azulene condensate of the present invention, in the general formula (3), R ¹ and R ² are preferably an aromatic ring substituent which may have a substituent, and R ³ to R ¹⁰ is preferably a non-aromatic ring substituents hydrogen atom or a 0 to 20 carbon atoms, particularly preferably a hydrogen atom.

{Conjugated chain linking group: L, L ¹ , L ² }
<Structure of conjugated chain linking group>
In the general formulas (1) and (3), L, L ¹ and L ² represent a conjugated chain linking group having 0 to 20 carbon atoms. Here, the conjugated chain linking group refers to a linear linking group that is bonded so that the conjugation of the porphyrin ring and the azulene ring is connected by a double bond or a triple bond. Specific examples thereof include the following vinylene group, ethynylene group, azo group, imino group and oligomers thereof, or combinations of two or more thereof (herein, k is an integer of 1 or more). ). Note that L, L ¹ and L ² are linear conjugated chains, particularly ethynylene groups or oligoethynylene groups, that is, the porphyrin-azulene condensate of the present invention is represented by the general formula (2). It is preferable in terms of improving photon absorption characteristics.

  Here, “oligo ………… group” refers to those in which k is 10 or less, for example, 2 to 10, particularly 2 to 4.

  In general formula (2), m represents an integer of 1 to 10. The smaller number of m is preferable in view of stability of the porphyrin-azulene condensate of the present invention and prevention of excessively long absorption wavelength, and particularly preferably 1 to 2. When n is 2 or more, each m may be the same or different, but the same is preferable in terms of the synthesis of the porphyrin-azulene condensate.

In the general formula (1), when n is 2 or more and a plurality of L are present, each L or L ¹ and L ² in the general formula (3) may be the same as or different from each other. Each L or L ¹ and L ² are preferably the same from the viewpoint of synthesis of the porphyrin-azulene condensate, but not the same from the viewpoint of improving the solubility in a solvent.

<Substitution position of L to porphyrin ring P>
L may be bonded to any carbon atom in the porphyrin ring, but L is bonded to the meso position of the porphyrin ring from the viewpoint of stability of the porphyrin-azulene condensate of the present invention, that is, the present invention. The porphyrin-azulene condensate is preferably represented by the general formula (3).

{N}
In general formula (1), (2), n represents the integer of 1-12. The larger the value of n, the better in terms of improving the two-photon absorption characteristics of the porphyrin-azulene condensate of the present invention, but the smaller the value, the better in terms of synthesis. In general formulas (1) to (3), n is particularly Preferably it is 2-4.

{Azulene ring substituent: A, A ¹ , A ² }
In the general formulas (1) to (3), the azulene ring substituents A, A ¹ and A ² represent an azulene ring substituent which may have a substituent other than the introduction position of L, L ¹ and L ^2. To express. In this case, the substituent that the azulene ring substituent may have corresponds to the substituent that the porphyrin ring may have. A, A ¹ and A ² preferably have these substituents in terms of improving the solubility of the porphyrin-azulene condensate of the present invention in a solvent, but may not have them. It is preferable in terms of improving the two-photon absorption characteristics.

In the general formulas (1) and (2), when n is 2 or more and a plurality of A are present, each A, or A ¹ and A ² in the general formula (3) are the same or different from each other. Also good. Each A or A ¹ and A ² are preferably the same from the viewpoint of synthesis of the porphyrin-azulene condensate, but not the same from the viewpoint of improving the solubility in a solvent.

<Substitution positions of L, L ¹ and L ² to azulene ring substituents A, A ¹ and A ² >
The substitution positions of L, L ¹ , and L ^{2 on} the azulene ring substituents A, A ¹ , and A ² may be substituted with positions at which the azulene ring substituents function as electron accepting groups. It is preferable in terms of improving photon absorption characteristics. Although this substitution position varies depending on the presence or absence of a substituent introduced into the azulene ring substituent and the type of the substituent, specifically, the 8th, 6th and 4th positions are preferred in the following structural formula.
On the other hand, in the point that the one-photon absorption effect can be further reduced, the positions of substitution of L, L ¹ and L ^{2 on} the azulene ring substituents A, A ¹ and A ² are the positions where the azulene ring substituents function as electron donating groups. Specifically, in the following structural formula, the 1st, 3rd, 5th and 7th positions are preferable.

{M ¹ }
In the general formula (3), M ¹ represents a hydrogen atom or a divalent or higher metal ion. The metal element of the metal ion is not particularly limited as long as it can coordinate inside the porphyrin ring. For example, Mg, Al, Si, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Mo, Ru, Rh, Pd, Ag, Pt, Au, Er, etc. are mentioned.
Of these, Co, Ni, Cu, and Zn are particularly preferable from the economical viewpoint.

When M ¹ is a trivalent or higher metal ion, it may further have a counter anion having 0 to 20 carbon atoms. Specific examples of the counter anion include water, alcohol, phenol, carboxylic acid, phosphonic acid, halogen, perchloric acid, periodic acid, cyanic acid, isocyanic acid, isothiocyanic acid, azide, nitric acid, carbonic acid, hydrogencarbonate, Substituted or unsubstituted sulfuric acid (sulfuric acid, hydrosulfuric acid, methylsulfuric acid, etc.), methanesulfonic acid, trifluoromethanesulfonic acid, tosylic acid, substituted or unsubstituted phosphoric acid (phosphoric acid, hydrophosphoric acid, dihydrogen phosphate) Acid, phenylphosphoric acid, etc.), phosphorous hexafluoride, antimony hexafluoride, substituted or unsubstituted phosphinic acid (phosphinic acid, methylphosphinic acid etc.), substituted or unsubstituted boronic acid (tetraphenylboronic acid etc.), Examples include anionized benzenesulfonic acid, acetic acid, trifluoroacetic acid and the like.
Among these, from the viewpoint of synthesis, a hydroxyl anion, a halogen anion, a boron tetrafluoride anion, a phosphorus hexafluoride anion and the like are preferable.

{Preferred example}
The porphyrin-azulene condensate of the present invention is particularly preferably represented by the following general formula (4).

（式（４）中、Ｒ^１１〜Ｒ^２０はそれぞれ独立に水素原子、置換基を有していても良い芳香環置換基、または炭素数０〜２０の非芳香環置換基を表し、Ａ^３およびＡ^４はそれぞれ独立に置換基を有していても良いアズレン環置換基を表し、Ｍ^２は２個の水素原子もしくは２価以上の金属イオンを表し、ｐおよびｑはそれぞれ独立に１〜１２の整数を表す。なお、Ｍ^２が３価以上の金属イオンである場合、さらに炭素数０〜２０のカウンターアニオンを有していても良い。）

(Expressed in the formula ^{(4), R} 11 ~R ²⁰ each independently represent a hydrogen atom, which may have a substituent aromatic ring substituent, or a non-aromatic ring substituents 0 to 20 carbon atoms, ^{A 3} And A ⁴ each independently represents an optionally substituted azulene ring substituent, M ² represents two hydrogen atoms or a divalent or higher metal ion, and p and q each independently represent 1 to It represents an integer of 12. In addition, when M ² is a trivalent or higher metal ion, it may further have a counter anion having 0 to 20 carbon atoms.

^<R 11 ~R ^20>
R ^{11 to} R ²⁰ each independently represent a hydrogen atom, an aromatic ring substituent which may have a substituent, or a non-aromatic ring substituent having 0 to 20 carbon atoms. Specific examples thereof include the substituents mentioned as the substituents (R ^{1 to} R ^{10 in} the general formula (3)) that the above-described porphyrin ring: P may have.

From the viewpoint of stability of the porphyrin-azulene condensate of the present invention, R ¹¹ and R ¹² are preferably aromatic ring substituents which may have a substituent, and R ^{13 to} R ²⁰ are hydrogen atoms. Or a non-aromatic ring substituent having 0 to 20 carbon atoms, particularly preferably a hydrogen atom.

<P, q>
p and q each independently represents an integer of 1 to 10. Among these, the smaller numbers of p and q are preferable in view of stability of the porphyrin-azulene condensate of the present invention and prevention of excessively long absorption wavelength, and it is particularly preferable that the number is 1 or 2 respectively. In addition, it is preferable in the synthetic | combination surface of a porphyrin-azulene condensate that p and q are the same.

<A ³ ,A ^4>
A ³ and A ⁴ each independently represent an azulene ring substituent which may have a substituent. As specific examples thereof, specific examples of A in the above general formula (1) (A ¹ and A ^{2 in} general formula (3)) respectively correspond. Incidentally, porphyrins of the present invention that A ³ and A ⁴ are each the same - is preferred in the synthesis face of azulene condensate, it is preferred from the viewpoint of improving solubility in solvents not identical.

<M ² >
In General Formula (4), M ² represents a hydrogen atom or a divalent or higher-valent metal ion, and specific examples thereof include those exemplified as M ¹ in General Formula (3).

{Molecular weight of porphyrin-azulene condensate}
The porphyrin-azulene condensate of the present invention has a molecular weight of usually 2,000 or less, particularly preferably 1,500 or less, from the viewpoint of preventing the two-photon absorption characteristics from being lowered with an increase in molecular weight.
The porphyrin-azulene condensate of the present invention is usually preferably insoluble in water.

{Concrete example}
Specific examples of the skeleton structure of the porphyrin-azulene condensate of the present invention are illustrated below, but the porphyrin-azulene condensate of the present invention is not limited to these unless it exceeds the gist of the present invention. In the following, Ac represents an acetyl group, Et represents an ethyl group, and the following exemplary compounds may further have a substituent other than those shown below.

  Furthermore, as specific examples of the porphyrin-azulene condensate of the present invention, each substituent, linking group, and number of substituents in the general formula (4) mentioned as a particularly preferable example of the skeleton structure are shown in Table 1 below. What is shown is mentioned.

{Synthesis method}
The porphyrin-azulene condensate of the present invention can be synthesized, for example, by the following method.
A compound in which L is acetylene can be obtained by coupling azulene substituted with, for example, acetylene to a halogenated porphyrin using the Sonogashira reaction or the like in the following reaction formula. In the following, P represents a porphyrin ring, and A represents an azulene ring substituent.

{Two-photon absorption characteristics}
Preferred among the porphyrin-azulene condensates of the present invention are excellent in two-photon absorption characteristics. Here, the excellent two-photon absorption property means that the two-photon absorption cross-section of the porphyrin-azulene condensate according to the Z-Scan method is usually 5,000 GM or more, preferably 7,000 GM or more, particularly preferably 10,000 GM or more. In the measurement by the pump-probe method, there is no one-photon absorption effect, and the two-photon absorption cross section is usually 500 GM or more, preferably 1,000 GM or more, particularly preferably 2,000 GM or more (nitrobenzene = 0) .11GM). The determination of the presence or absence of the one-photon absorption effect will be described in detail in the section of the examples.

{Usage}
The novel porphyrin-azulene condensate of the present invention can be applied to various uses such as an electron transport material, an optical or magnetic recording material, a battery material, a display member material, and a medical material in addition to the two-photon absorption material described later. is there.

[Two-photon absorption material]
The two-photon absorption material of the present invention contains the porphyrin-azulene condensate of the present invention as described above.
In addition, in the two-photon absorption material of the present invention, one type of the porphyrin-azulene condensate of the present invention may be contained alone, or two or more types may be mixed and contained.

The two-photon absorption material of the present invention is a block or powder in the state of a powdery crystal of one kind of the porphyrin-azulene condensate of the present invention or a mixture of two or more kinds of the porphyrin-azulene condensate; or Dissolved or dispersed in solvent, polymer, gel such as hexane, toluene, xylene, methylene chloride, chloroform, ether, tetrahydrofuran, ethyl acetate, acetone, 2-butanone, methanol, ethanol, trifluoromethylbenzene, acetic acid, triethylamine As a liquid; or as a thin film obtained by removing the solvent after applying such a liquid to a substrate; it can be used for various applications.
For example, an optical recording medium can be produced using a two-photon absorption material containing the porphyrin-azulene condensate of the present invention.

  The two-photon absorption material contains the novel porphyrin-azulene condensate of the present invention after the material has been subjected to treatments such as decomposition and extraction, and then, for example, liquid chromatography-mass spectrometry (LC- MS) or nuclear magnetic resonance spectroscopy (NMR) can be used for analysis.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist.

[Synthesis Example of Porphyrin-Azulene Condensate of the Present Invention]
Example 1: Synthesis of the exemplified compound (C-1)

  5,15-bis- (3,5-di-tert-butylphenyl) -10,20-bis- (triisopropylsilylethynyl) -porphyrin zinc complex (348 mg) was dissolved in tetrahydrofuran (THF) (60 mL), and 0 After cooling to ° C., tetrabutylammonium fluoride hydrate (TBAF) (203 mg) was added. After stirring at room temperature for 15 minutes, saturated brine was added to stop the reaction. The organic layer was extracted from this mixture with dichloromethane and dried over anhydrous sodium sulfate. The organic layer was concentrated and recrystallized to obtain 5,15-bis- (3,5-di-tert-butylphenyl) -10,20-diethynyl-porphyrin zinc complex. Yield 206.1 mg (82%)

Under an argon atmosphere, 3-iodo-1-hexyloxycarbonylazulene (60 mg), triethylamine (1.6 mL), Pd (Ph ₃ P) ₄ (18 mg), and CuI (3 mg) were dissolved in 6 mL of THF with stirring. A solution of 5,15-bis- (3,5-di-tert-butylphenyl) -10,20-diethynyl-porphyrin zinc complex (75 mg) in THF (30 mL) was slowly added dropwise thereto at room temperature. The reaction mixture was stirred at room temperature for 15 hours, and then saturated brine was added to stop the reaction. The organic layer was extracted with chloroform and dried over anhydrous sodium sulfate.
After distilling off the solvent, the residue is separated by column chromatography (silica gel, THF / hexane = 5/1 · 2/1 · THF is used to remove the green band in order) and GPC (THF). This gave the target compound (C-1). Yield 44.2 mg (43%)

Example 2: Synthesis of the exemplified compound (C-2)

Under argon atmosphere, 6-bromo-1,3-bis (hexyloxycarbonyl) -azulene (60 mg), triethylamine (1.3 mL), Pd (Ph ₃ P) ₄ (15 mg) and CuI (3 mg) were stirred in 5 mL of THF. While melting. To this, a THF (25 mL) solution of 5,15-bis- (3,5-di-tert-butylphenyl) -10,20-diethynyl-porphyrin zinc complex (62 mg) synthesized in the same manner as in Example 1 was added. It was slowly added dropwise at room temperature. The reaction mixture was stirred at room temperature for 12 hours, and then saturated brine was added to stop the reaction. The organic layer was extracted with chloroform and dried over anhydrous sodium sulfate. After the solvent was distilled off, the target compound (C-2) was obtained by the same operation as in Example 1. Yield 87.9 mg (87%)

Example 3: Synthesis of the exemplified compound (C-3)

  Under an argon atmosphere, 5,15-bis- (3,5-di-tert-butylphenyl) -10,20-diethynyl-porphyrin zinc complex (230 mg) synthesized in the same manner as in Example 1 was mixed with a THF / pyridine mixed solvent. (THF 30 mL / pyridine 0.3 mL) was dissolved, and LiHMDS (0.58 mL, 1M solution) was added dropwise. After stirring at room temperature for 10 minutes, triisopropylsilyl chloride (0.19 mL) was added, and the mixture was further stirred for 30 minutes. Thereafter, 1M aqueous potassium hydroxide solution was added to stop the reaction, and the organic layer was extracted with chloroform. The organic layer was dried over anhydrous sodium sulfate and concentrated, and the residue was separated and purified by column chromatography (silica gel, hexane / THF / pyridine = 10/2/1) to give 5-ethynyl-15-triisopropylsilyl. Ethinyl-10,20-bis- (3,5-di-tert-butylphenyl) -porphyrin zinc complex was obtained. Yield 105.9 mg (39%)

Under an argon atmosphere, 3-iodo-1-hexyloxycarbonylazulene (60 mg), triethylamine (1.5 mL), Pd (Ph ₃ P) ₄ (18 mg), and CuI (3 mg) were dissolved in 10 mL of THF with stirring. To this was slowly added dropwise a solution of 5-ethynyl-15-triisopropylsilylethynyl-10,20-bis- (3,5-di-tert-butylphenyl) -porphyrin zinc complex (180 mg) in THF (20 mL) at room temperature. did. The reaction mixture was stirred at room temperature for 24 hours, and then saturated brine was added to stop the reaction. The organic layer was extracted with chloroform and dried over anhydrous sodium sulfate. After distilling off the solvent, 5-triisopropylsilylethynyl-15- (3-hexyloxycarbonyl-1-azurenylethynyl) -10,20-bis- was separated by column chromatography in the same manner as in Example 1. A (3,5-di-tert-butylphenyl) -porphyrin zinc complex was obtained. Yield 117.7 mg (62%)

  5-Triisopropylsilylethynyl-15- (3-hexyloxycarbonyl-1-azulenylethynyl) -10,20-bis- (3,5-di-tert-butylphenyl) -porphyrin zinc complex (50 mg) was dissolved in THF. / Pyridine mixed solvent (10 mL / 0.1 mL) was dissolved, cooled to 0 ° C., and TBAF (13 mg) was added. The reaction mixture was stirred for 10 minutes and then quenched with saturated brine. The organic layer was extracted with chloroform, dried over anhydrous sodium sulfate, and the solvent was distilled off to remove 5-ethynyl-15- (3-hexyloxycarbonyl-1-azurenylethynyl) -10,20-bis- ( 3,5-Di-tert-butylphenyl) -porphyrin zinc complex was obtained. Yield 38.8 mg (89%)

Under an argon atmosphere, 6-bromo-1,3-bis (hexyloxycarbonyl) -azulene (20 mg), triethylamine (0.4 mL), Pd (Ph ₃ P) ₄ (5 mg), and CuI (1 mg) were stirred in 3 mL of THF. While melting. To this was added 5-ethynyl-15- (3-hexyloxycarbonyl-1-azurenylethynyl) -10,20-bis- (3,5-di-tert-butylphenyl) -porphyrin zinc complex (55 mg) in THF ( 7 mL) solution was slowly added dropwise at room temperature. The reaction mixture was stirred at room temperature for 6 hours, and then saturated brine was added to stop the reaction. The organic layer was extracted with chloroform and dried over anhydrous sodium sulfate. After the solvent was distilled off, the target compound (C-3) was obtained by the same operation as in Example 1. Yield 53.5 mg (86%)

[Evaluation of Two-Photon Absorption Cross Section / Z-scan Method]
Compounds (C-1) to (C-3) were dissolved in toluene to give a 0.150 mM solution.
The two-photon absorption cross section of the solution was measured by the method shown below.

  The evaluation of the two-photon absorption cross section by the Z-scan method is as follows: Guang S. He, Lixiang Yuan, Ning Cheng, Jayant D. Bhawalkar, Paras N. Prasad, Lawrence L. Brott, Stephen J. Clarson, Bruce A. Reinhardt, J Opt. Soc. Am. B Vol. 14, No. 5 (1997) pp. 1079-1087. A schematic diagram of the measurement system is shown in FIG.

  In FIG. 1, reference numeral 1 denotes a titanium sapphire laser as a measurement light source, which uses Integra manufactured by Quantronix. Reference numerals 2A and 2B denote photo detectors, which were manufactured by NewFocus: Cylindrical detector MODEL 818-SL. 3A and 3B are amplifiers, manufactured by Stanford Research Systems: LOW-NOISE CURRENT PREAMPLIFIER MODEL SR570 and gated integrator & box car averager (GATED INTEGRATOR & BOXCAR AVERAGER) MODEL SR250 was used. 4 is a beam splitter, and 5 is a sample cell made of quartz. 6 is a personal computer (PC).

The measurement light source 1 was a femtosecond titanium sapphire laser (wavelength: 800 nm, pulse width: 120 fs, repetition rate: 1 kHz, average output: 2 W, intensity: 2 mJ / pulse, beam diameter: 10 mmφ, peak power: 20 GW). Part of the laser output (hereinafter referred to as reference light) was branched by the beam splitter 4, and the intensity of the incident light intensity was corrected by measuring the intensity with the photodetector 2A through the ND filter 7A. The remainder of the laser output was attenuated to about 10 mW by the ND filter 7B and then condensed by the condenser lens 8. A Z-scan measurement was performed by placing a sample cell (optical path length: 10 mm) 5 filled with a sample solution in the collected optical path portion and moving the position along the optical path. Thus changing the excitation light density in the range of ^{1GW / cm 2 ~40GW / cm 2} . As the sample cell 5, a quartz cell having an optical path length of 10 mm was used.

  Laser light transmitted through the sample cell 5 (hereinafter referred to as transmitted light) is appropriately attenuated by the ND filter 7C, passed through a colored glass filter 7D such as R72 manufactured by HOYA Corporation, and then the intensity was measured by the photodetector 2B. . This measurement was performed for a plurality of excitation light densities, and the normalized solution transmitted light intensity was obtained by dividing the transmitted light intensity by the reference light intensity. Reference numeral 9 denotes a shutter.

  The same measurement was performed by filling the sample cell with only the solvent using the same measuring apparatus, and the normalized solvent transmitted light intensity was obtained. Further, the transmittance was determined by dividing the normalized solution transmitted light intensity by the normalized solvent transmitted light intensity.

The dependence of the transmittance on the excitation light density was measured by the procedure as described above, and the result was fitted by the theoretical formula (i) described in the above document to obtain the nonlinear absorption coefficient.
Ti = [ln (1 + I ₀ L ₀ β)] / I ₀ L ₀ β (i)
(In formula (i), Ti represents transmittance (%), I ₀ represents excitation light density [GW / cm ² ], L ₀ represents sample cell length [cm], and β represents nonlinear absorption coefficient [cm / GW]. .)

From this nonlinear absorption coefficient, the two-photon absorption cross section δ was determined by the following formula (ii) (the unit of δ is 1GM = 1 × 10 ⁻⁵⁰ cm ⁴ · s · photon ⁻¹ ).
_{δ = 1000 × hνβ / N A} C (ii)
((In ii) formula, h is Planck's constant [J · s], ν is the frequency of the incident laser light ^[s -1], _{N A} is Avogadro's number, C is concentration of solution [mol / L].)

  In the above system, the numerical value of the compound (AF-50) represented by the following structural formula is obtained from 45 GM to 55 GM. In order to normalize the two-photon absorption cross section, all the two-photon absorption cross-section values are measured for AF-50 after measuring the sample, and the two-photon absorption cross-section of the AF-50 is 50 GM. Calculated.

  Table 2 shows the evaluation results of the two-photon absorption cross section measured under the above conditions. From Table 2, it is clear that the porphyrin-azulene condensate of the present invention exhibits good two-photon absorption characteristics.

[Evaluation of two-photon absorption cross section, pump-probe method 1]
The magnitude of the two-photon absorption effect of the compound (C-2) was evaluated.
The evaluation method was a pump-probe method. The experimental system is shown in FIG. In FIG. 2, 11 is a titanium sapphire laser, 12 is a beam splitter, 13, 14 and 15 are reflecting mirrors, 16 and 19 are condensing lenses, 17 is a sample, 18 is an aperture, 20 is a detector, 21 is a chopper, 22 Is a lock-in amplifier, 23 is pump light, 24 is probe light, and 25 is a delay line. In this system, the laser light emitted from the titanium sapphire laser 11 is divided into the pump light 23 and the probe light 24 by the beam splitter 12, condensed by the condenser lens 16, and then irradiated to the sample 17. Only the probe light is effectively incident on the detector 20 by the aperture 18. The transmittance of the probe light 24 is changed by the incidence of the pump light 23. From the state of the change, it is possible to estimate the magnitude of the two-photon absorption coefficient. That is, when there is no pump light, the probe light 24 is almost transmitted through the sample 17 (which is transparent at the laser light wavelength but uses absorption at half the wavelength range), but when the pump light 23 enters. Probe light is absorbed by the two-photon absorption process. Eventually, since the transmittance of the probe light decreases, the two-photon absorption coefficient can be known by observing the decrease.

  Since the laser 11 to be used is a pulse, it is necessary to match the temporal timing of the pump pulse and the probe pulse. This can be done by changing the optical path length of the pump light 23 by moving the delay line 25 back and forth. The transmittance was estimated by the lock-in method. In this embodiment, the pump light 23 is chopped. The titanium sapphire laser beam used this time had a wavelength of 796 nm, a pulse width of 130 fs, and a repetition frequency of 1 kHz (the pulse width was calculated from a correlation waveform using a BBO crystal). A detector was used as the detector 20.

  In the present invention, the two-photon absorption coefficient is calculated by reading the transmittance change in each sample and measuring it relative to the standard sample. In addition, the estimation of the two-photon absorption coefficient of the standard sample was based on the value combination with the Z-Scan method described above. That is, in the Z-Scan method, the absolute value of the two-photon absorption coefficient of each sample can be easily estimated. Therefore, both the pump-probe method and the Z-Scan method are measured for a common sample, and the results are obtained. The absolute value of the standard sample used for the pump-probe method was determined.

  In the present invention, the two-photon absorption coefficient of a toluene solution (0.01 mol / l) of 4- (N, N-diethylamino) -β-nitrostyrene (DEANST) is estimated by the Z-Scan method, The absolute value of the photon absorption coefficient, and then in the pump-probe method, the change in the probe light transmittance of each sample is compared with the DEANST toluene solution to estimate the absolute value of the two-photon absorption coefficient of each sample. did. However, as the value of the two-photon absorption coefficient of each sample in the following examples, the value of nitrobenzene was calculated from the comparison with the DEANST solution, and this was used as a secondary reference sample. Nitrobenzene was used because it is commercially available and fresh samples can be obtained constantly. The two-photon absorption coefficient of nitrobenzene was 0.025 cm / GW.

  As shown in the following examples, the reason why the pump-probe method is used instead of the Z-Scan method is because the presence or absence of the contribution of the thermal effect can be easily known.

The measurement result about the THF (tetrahydrofuran) solution of the compound (C-2) of different concentration is shown in FIG. Intensity density of the laser beam during the measurement, the pump light 100GW / cm ^2, the probe beam was 6.4GW / cm ^2. It was found that the change in transmittance due to two-photon absorption is proportional to the concentration. Based on the results of FIG. 3, the two-photon absorption coefficient at each concentration was determined, and the contribution of THF was subtracted, and the two-photon absorption cross section δ of the compound (C-2) itself was calculated to be δ = 2700 GM. The δ value of nitrobenzene is 0.11 GM. The large δ value of the compound (C-2) obtained this time indicates that this molecule can be a suitable two-photon absorption material. The two-photon absorption cross section δ (GM) is obtained as follows when the two-photon absorption coefficient is β (cm / GW) (as described above, the β value is obtained from the magnitude of the change in the transmittance of the probe light. ).

Here, h is Planck's constant, [nu is the number of vibrations of the laser beam, N _A is Avogadro's number, C is the concentration of the solution.

  FIG. 4 shows the experimental results of measuring the change in the transmittance of the probe light while moving the delay line 25 of FIG. 2 back and forth and changing the timing of the pump pulse and the probe pulse. Although this time waveform is referred to as a correlation waveform, it is possible to verify whether or not there is a contribution of a phenomenon having a long relaxation time such as the pulse width of the laser beam used or the thermal effect.

  In FIG. 4, the delay time is positive when the probe pulse first enters the sample.

  Here, in the two-photon absorption process, if a phenomenon with a long relaxation time such as a thermal effect is involved (the thermal effect has a relaxation time of about microseconds or more), the pump pulse is more than the probe pulse. In the time region where the sample first arrives (region where the delay time is negative in FIG. 4), the signal light does not immediately become zero, but the tail is pulled. In the concentration range tested this time, almost no tail is seen, and as a result, it is presumed that there was no contribution such as thermal effect. Further, since the correlation width (half-value width) is estimated to be 188 fs from FIG. 4, assuming that the waveform is Gaussian, the pulse width of the used laser pulse is calculated to be 133 fs. Even with the BBO crystal, when the pulse width of this laser is measured, it becomes 130 fs, and this value of 133 fs obtained this time further supports the correctness of the present experimental result. This is because when a phenomenon other than the two-photon absorption process (mainly one-photon absorption) is involved, the pulse width may become wide (the calculated value becomes larger than the actually measured value).

  As described above, it can be concluded that the compound (C-2) has a good two-photon absorption property and has a suppressed contribution such as a thermal effect, that is, a compound capable of removing the one-photon absorption effect.

[Evaluation of the two-photon absorption cross section / pump / probe method 2]
The magnitude of the two-photon absorption effect of the compound (C-1) was evaluated.
The evaluation method was a pump-probe method. Evaluation of this material was based on the experimental system shown in FIG. In FIG. 5, 11 is a titanium sapphire laser, 12 is a beam splitter, 13, 14 and 15 are reflecting mirrors, 16A is a concave mirror, 19 is a condenser lens, 17 is a sample, 18 is an aperture, 20 is a detector, and 21 is a chopper. , 22 is a lock-in amplifier, 23 is pump light, 24 is probe light, and 25 is a delay line. In this system, the laser light emitted from the titanium sapphire laser 11 is divided into the pump light 23 and the probe light 24 by the beam splitter 12, condensed by the concave mirror 16, and then irradiated to the sample 17, and effectively by the aperture 18. Only the probe light is incident on the detector 20.

  The two-photon absorption coefficient was estimated by the same method as in the case of the above compound (C-2). However, in this measurement system, pump light and probe light were chopped at different frequencies, and lock-in detection was performed using the sum frequency. The titanium sapphire laser beam used this time had a wavelength of 796 nm, a pulse width of 26 fs, and a repetition frequency of 1 kHz (the pulse width was calculated from a correlation waveform using a BBO crystal). The reason why the condensing of the beam is the concave mirror 16A regardless of the lens is that the laser pulse used here is as short as 26 fs, so that the characteristics can be utilized.

FIG. 6 shows the result of examining the solution concentration dependence of the signal intensity for the THF solution of the compound (C-1). Excitation light density in the measurement, the pump light 15GW / cm ^2, the probe light was 1.5 GW / cm ^2. Again, the transmittance change due to two-photon absorption was found to be proportional to the concentration. When the two-photon absorption cross section δ of the compound (C-1) was determined by the same method as in the case of the compound (C-2), δ = 680 GM. This is a value of about ¼ that of the compound (C-2), but this difference is considered to reflect the difference in absorbance between the two molecules at a wavelength of 400 nm. It was found that the compound (C-1) also showed a sufficiently large δ value.

  For compound (C-1), an experiment was conducted to confirm that the δ value obtained this time was based on a pure two-photon absorption process. FIG. 7 shows the result. In the compound (C-1), like the compound (C-2), there is not much tail in the concentration range tested this time, and as a result, it can be inferred that the contribution of the thermal effect and the like can be ignored. Further, the correlation width estimated from FIG. 7 was 70 fs, and when the pulse width of the laser pulse used was calculated assuming that the waveform was Gaussian, it was calculated to be 28 fs. Since the pulse width estimated by the BBO crystal is 26 fs, the reliability of estimation of the current δ value is supported by this measurement result. That is, it can be concluded that the compound (C-1) has a good two-photon absorption property and has a very small contribution such as a thermal effect.

  As described above, since the porphyrin-azulene condensate of the present invention causes high two-photon absorption, it can be applied to, for example, a three-dimensional optical storage medium in which two-photon absorption thin films are stacked. In addition, in a three-dimensional medium in which the two-photon absorption material composed of the porphyrin-azulene condensate of the present invention is uniformly dispersed, the present invention can be applied to a device for arbitrarily moving a laser beam irradiation spot to perform three-dimensional drawing. Is possible.

In an Example, it is a measurement system schematic of the apparatus used for the measurement of the two-photon absorption cross section by the Z-scan method of a porphyrin-azulene condensate. In an Example, it is a measurement system schematic of the apparatus used for the measurement of the two-photon absorption cross section by the pump probe method 1 of a porphyrin-azulene condensate. It is a measurement result of the transmittance | permeability change by two photon absorption about the THF (tetrahydrofuran) solution of the compound (C-2) of a different density | concentration in an Example. 2 is a result of an experiment in which a change in the transmittance of the probe light is measured while changing the timing of the pump pulse and the probe pulse by moving the delay line 25 of the apparatus of FIG. 2 back and forth. In an Example, it is a measuring system schematic of the apparatus used for the measurement of the two-photon absorption cross section by the pump probe method 2 of a porphyrin-azulene condensate. In an Example, it is the result of having investigated the solution concentration dependence of the signal strength about the THF solution of a compound (C-1). 5 is a result of an experiment in which the change in the transmittance of the probe light is measured while changing the timing of the pump pulse and the probe pulse by moving the delay line 25 of the apparatus of FIG. 5 back and forth in the example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Measurement light source 2A, 2B Photo detector 3A, 3B Amplifier 4 Beam splitter 5 Sample cell 6 Personal computer 7A, 7B, 7C ND filter 8 Condensing lens 9 Shutter 11 Titanium sapphire laser 12 Beam splitter 13, 14, 15 Reflectors 16, 19 Condenser lens 16A Concave mirror 17 Sample 18 Aperture 20 Detector 21 Chopper 22 Lock-in amplifier 23 Pump light 24 Probe light 25 Delay line

Claims (5)

A porphyrin-azulene condensate represented by the following general formula (1).

(In formula (1), P represents a porphyrin ring which may have a substituent, L represents a conjugated chain linking group having 0 to 20 carbon atoms, and A may have a substituent. Represents an azulene ring substituent, and n represents an integer of 1 to 12. When n is 2 or more, each L and A may be the same or different. The porphyrin-azulene condensate represented by the following general formula (2) in claim 1.

(In the formula (2), P represents an optionally substituted porphyrin ring, A represents an optionally substituted azulene ring substituent, and m represents an integer of 1 to 10. , N represents an integer of 1 to 12. When n is 2 or more, m and A may be the same or different. The porphyrin-azulene condensate represented by the following general formula (3) in claim 1.

(Expressed in the formula (3), R ¹ ~R ¹⁰ independently represents a hydrogen atom, which may have a substituent aromatic ring substituent, or a non-aromatic ring substituents 0 to 20 carbon atoms, L ¹ And L ² each independently represents a conjugated chain linking group having 0 to 20 carbon atoms, A ¹ and A ² each independently represent an azulene ring substituent which may have a substituent, and M ¹ represents 2 Represents a hydrogen atom or a metal ion having a valence of 2 or more, and when M ¹ is a metal ion having a valence of 3 or more, it may further have a counter anion having 0 to 20 carbon atoms.) The porphyrin-azulene condensate represented by the following general formula (4) according to claim 3.

(Expressed in the formula ^{(4), R} 11 ~R ²⁰ each independently represent a hydrogen atom, which may have a substituent aromatic ring substituent, or a non-aromatic ring substituents 0 to 20 carbon atoms, ^{A 3} And A ⁴ each independently represents an optionally substituted azulene ring substituent, M ² represents two hydrogen atoms or a divalent or higher metal ion, and p and q each independently represent 1 to It represents an integer of 12. In addition, when M ² is a trivalent or higher metal ion, it may further have a counter anion having 0 to 20 carbon atoms.   A two-photon absorption material comprising the porphyrin-azulene condensate according to any one of claims 1 to 4.

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