JP5585902B2 - Method for producing two-photon absorption film comprising inorganic compound-organic compound composite - Google Patents

Description

  The present invention relates to a novel two-photon absorption film. Specifically, it is a two-photon absorption film made of a composite of an inorganic compound and an organic compound in which a specific organic compound is adsorbed on a clay mineral that is an inorganic ion exchanger.

  In recent years, among the third-order nonlinear optical materials, two-photon absorption materials have attracted attention, and various applications are expected in optical devices and bio-related.

  Two-photon absorption is a phenomenon in which a compound is excited by simultaneously absorbing two photons. In other words, in the energy region where there is no absorption band of the compound, this is a phenomenon in which two photons are simultaneously absorbed and electrons transition to an excited state.

  Even when the compound is excited by two-photon absorption, the energy is released in various forms at the stage of releasing the energy in the same manner as the one-photon absorption excitation. For example, there are those that release energy as fluorescence, phosphorescence or heat in the deactivation process.

  Since the efficiency of two-photon absorption is proportional to the square of the applied photoelectric field, it is excited by condensing the laser light with a lens in a three-dimensional space inside the substance and increasing the electric field strength at the focal point. High spatial resolution can be given to photoexcitation, such as causing two-photon absorption at one point, causing two-photon emission only at the focal point, or causing high heat to cause a chemical change. For this reason, the inside of an object, especially a translucent object can be processed, and special light emission can be performed in the deep part of the object. In particular, application to a recording medium for optical recording has many advantages over conventional one-photon excitation from the viewpoint of three-dimensional spatial resolution.

  However, the two-photon absorption material generally has an extremely small absorption cross section, and it is necessary to use an expensive and large-sized pulse laser light source having a large peak output such as a femtosecond laser.

  In order to solve such a problem, development of a material with higher two-photon absorption efficiency is desired, and various compounds have been proposed so far. For example, a carbazole derivative (Patent Document 1), a compound having an iodonium salt structure (Patent Document 2), a tetrabenzoporphyrin derivative (Patent Document 3), a metal porphyrin, a phthalocyanine compound (Patent Document 4), a tetraaza as an organic compound Porphyrin compounds (Patent Document 5) or ketones represented by the following general formula.

（Ｘ^１、Ｘ^２は置換もしくは無置換のアリール基、または置換もしくは無置換のヘテロ環基を表し、同一でも異なっていてもよく、Ｒ^１、Ｒ^２、Ｒ^３およびＲ^４は、それぞれ独立に水素原子、または置換基、Ｒ^１、Ｒ^２、Ｒ^３およびＲ^４のうちのいくつかが互いに結合して環を形成してもよく、ｎおよびｍは２以上の場合、複数個のＲ^１、Ｒ^２、Ｒ^３およびＲ^４は同一でも、それぞれ異なっていてもよく、ｎ及びｍは、それぞれ独立に１〜４の整数を表す。）（特許文献６）など多数が提案されている。また無機−有機複合体物質としては、ポリマーの中に金属微粒子を分散させたもの（非特許文献１）、有機金属錯体（非特許文献２）、粘土鉱物に有機色素を吸着させたもの（非特許文献３）などが提案されている。

(X ¹ and X ² represent a substituted or unsubstituted aryl group, or a substituted or unsubstituted heterocyclic group, which may be the same or different, and R ¹ , R ² , R ³ and R ⁴ are each independently And a hydrogen atom or a substituent, some of R ¹ , R ² , R ³ and R ⁴ may be bonded to each other to form a ring, and when n and m are 2 or more, a plurality of R ¹ , R ² , R ³ and R ⁴ may be the same or different, and n and m each independently represent an integer of 1 to 4.) (Patent Document 6) . Inorganic-organic composite materials include those in which fine metal particles are dispersed in a polymer (Non-patent Document 1), organometallic complexes (Non-Patent Document 2), and organic minerals adsorbed on clay minerals (Non-Patent Document 1). Patent Document 3) has been proposed.

  However, even with these proposals, sufficient effects are not yet obtained, an expensive and large device is required to generate strong light, and excitation is possible with a cheaper light source to realize the application. In other words, development of a material having high two-photon absorption efficiency has been desired.

  In view of the above situation, the present invention aims to develop a material with high two-photon absorption efficiency, paying attention to a composite of a clay mineral and an organic compound, and as a result of repeated research, succeeded in finding an extremely efficient material. did.

Conventionally, as a complex of a clay mineral and an organic compound, in Non-Patent Document 3, synthetic saponite and 1,4-bis (2,5-dimethoxy-4- {2- [4- (N-methyl) pyridinium] ethenyl} -phenyl) butadiy
It has been reported that the combination of ne triflate (MPPBT) increased the two-photon absorption cross section by 2.5 times in the dispersion medium. The reason for the increase shown in this paper is the effect of aligning the direction of the compound and the direction of polarization of the excitation light, the effect of suppressing the rotation of the compound and the strong conjugation of the compound, and the adsorption of the dye to the exchange capacity of the clay The quantity (referred to as CEC ratio) is irrelevant.

In each of these conventionally proposed two-photon absorption materials, an improvement in absorption efficiency is certainly observed, but as described above, it is still not sufficient, and a two-photon absorption material having a larger absorption cross section is desired. It was.
JP 2001-264828 A JP-A-10-325968 JP-A-9-179153 JP-A-7-218939 JP-A-5-5916 JP 2003-183213 A NCStrandwitz, etal., J. Am. Chem. Soc., (2008) 130, 8280. S. Mazzucato, etal., Phys. Chem. Chem. Phys., (2007) 9, 2999. K. Kamada, et al., J. Phys. Chem. C, (2007) 111, 11193.

  In view of the above circumstances, the present invention is to provide a material having a large two-photon absorption cross-sectional area.

The main aspect of the present invention is a substituted or unsubstituted form that forms a chromophore in a dispersion medium of smectite dispersed in particles of 0.01 μm to several μm by dilutingly dispersing in a solution and stirring vigorously. By adding and stirring an organic compound in which an electron-withdrawing aromatic group and a substituted or unsubstituted aromatic group having an electron-donating group are bonded via a conjugated group, the ion exchange capacity of the smectite is increased. Of these, a method for producing a two-photon absorption film , in which an inorganic compound-organic compound complex in which 3 to 40% is adsorbed with the organic compound, is deposited to a thickness of 0.5 μm to 10 μm.

  Here, the electron withdrawing group is particularly preferably an aromatic group having at least one group selected from onium ion groups, and among them, an aromatic group having a quaternary ammonium group is excellent.

Further, smectite, saponite, Sokoraito, beidellite, hectorite, and Ri least one Der selected from among montmorillonite, in particular synthetic saponite are excellent.

As the electron-donating group, an amino group, an alkoxy group, an alkylthio group, a hydroxyl group, a halogen atom, an aromatic group having at least one group selected from the aromatic groups having an alkyl group such as, among others amino group The aromatic group it has is excellent.

  As these aromatic groups, monocyclic or polycyclic heterocyclic groups including nitrogen, oxygen, sulfur, selenium and the like, which are monocyclic groups consisting only of hydrocarbons, nitrogen atoms, oxygen atoms, sulfur atoms, selenium atoms, etc. There may be. Of course, the form which the hydrocarbon ring and the heterocycle compounded may be sufficient. A compound in which a substituted aromatic group having an electron withdrawing property is bonded to a substituent having an electron donating property via a conjugated group is particularly excellent.

Furthermore, specific examples of organic compounds adsorbed on smectite in the present invention include cyanine dyes, merocyanine dyes, hemicyanine dyes, and pyrylium dyes, and of course, a mixture of a plurality of these dyes. It may be.

Furthermore, the two-photon absorption film of the present invention requires specific consideration in the manufacturing process. That is, the smectite must be sufficiently refined to about 0.01 μm to several μm , and 3 to 40% of its ion exchange capacity must be adsorbed by the organic matter in a diluted state in the solution. In general, it is important that the solution is separated by filtration and the inorganic compound-organic compound complex is collected by being deposited on the filtration surface by about 0.5 μm to 10 μm .

The present invention has the 3-40% of the ion exchange capacity with the smectite is a clay mineral, location換又that form a chromophore and an aromatic group unsubstituted electron withdrawing, the electron donating group A two-photon absorption film comprising a composite of an inorganic compound and an organic compound adsorbed by an organic compound in which a substituted or unsubstituted aromatic group is bonded via a conjugated group, and on the smectite , of its exchange capacity 3 to 40%, preferably 5 to 20%, by adsorbing the organic compound, and forming a film having a thickness of 0.5 to 10 μm in a film shape, compared with the case where it is dispersed in a solvent. The absorption cross-sectional area per molecule is improved by a factor of 10 to 20 times at the maximum.

The greatest feature of the present invention is 3 to 40% of the ion exchange capacity of that solution dispersion of smectite particles, and it is particularly adsorb the organic material by 5-20%, the complex 0.5~10μm It is to form on a film | membrane with the thickness of .

The smectite used in the present invention is a layered silicate mineral, a form in which aluminum oxide and silicic acid are the main components, a sheet in which they are connected, forms a layer, and has an exchangeable cation such as sodium or calcium between the layers. belongs to.

  It has the property of adsorbing water, metal ions, etc., or organic substances in the gaps between the sheets.

Smectite used in the present invention, the layer-like silicate minerals der Lusa Ponaito, Sokoraito, beidellite, hectorite, a montmorillonite, among them synthetic saponite are preferred.

These smectites can be easily disintegrated and dispersed as particles of 0.01 μm to several μm by diluting them in a solvent such as water, dimethyl sulfoxide, alcohol, tetrahydrofuran, etc. and stirring vigorously. .

  The specific organic compound used in the present invention includes, in the molecule, an electron-withdrawing aromatic group of a substituted or unsubstituted aromatic group, and a substituted or unsubstituted aromatic group having an electron-donating group. Are bonded via a conjugated group, preferably a substituted or unsubstituted aromatic group is present at both ends of the compound, one is an electron-withdrawing group that forms a chromophore, and the other The aromatic group functions as an electron donating group, and both the aromatic groups are bonded via a conjugated group. However, the electron withdrawing group and the electron donating group are not necessarily present at both ends of the molecule, the electron withdrawing group is present at both ends of the molecule, and the electron donating group is present at the center of the molecule. It may be shaped or vice versa.

  Examples of these compounds include cyanine dyes, merocyanine dyes, hemicyanine dyes, and pyrylium dyes. For example, the following compounds can be exemplified.

本発明において、無機化合物−有機化合物複合体を得る方法の例は、水、アルコール、ジメチルホルムアルデヒド、テトラヒドロフラン、その他の分散媒中にスメクタイトを分散させ、これに有機化合物を加えて十分に撹拌することによってスメクタイトに有機化合物を所定量吸着させ、これをメンブランフィルターによって濾過し、メンブラン上に所定厚さだけ、複合体を堆積させ、これを基板上に移す方法等が用いられる。勿論、製膜方法は特に限定されるものではない。

In the present invention, an example of a method for obtaining an inorganic compound-organic compound complex is that smectite is dispersed in water, alcohol, dimethylformaldehyde, tetrahydrofuran, or other dispersion medium, and the organic compound is added thereto and sufficiently stirred. the smectite organic compound was Tokoro quantitative adsorbed, which was filtered by a membrane filter, only to a predetermined Teiatsu of the membrane, is deposited complexes, methods and the like are used to transfer it on board. Of course, the film forming method is not particularly limited.

  The two-photon absorption material obtained in the present invention has a high two-photon absorption cross-sectional area that has not been considered previously.

  The reason for this is not always clear, but the two-photon absorption cross-section area increases when complexed with clay only when a long-wavelength shift of the one-photon absorption spectrum occurs, and the one-photon absorption spectrum changes. It is confirmed with a plurality of dyes that the two-photon absorption cross-section does not increase without it.

  The cause of the long wavelength shift is that some molecules formed J aggregates. The constitution of the present invention is that if the J aggregate is fixed by complexing with clay, the two-photon absorption cross section always increases.

  The characteristic of the J aggregate is that it shifts to the lower wavenumber side, that is, the longer wavelength side than the absorption band of the dye alone, and produces a sharp absorption band.

  However, the specific organic compound used in the present invention generally has a large static dipole in the major axis direction, and it is considered that J-association is difficult to obtain due to electrostatic interaction between the dipoles. However, in the present invention, by fixing this on the clay, some other interaction acts between the molecules, the molecular charge transfer in the chromophore increases, and contributes to the formation of the J aggregate. it is conceivable that. Therefore, in the present invention, a system in which a J aggregate is formed by a complex with clay is an object of the present invention, and includes a large number of compounds. That is, the essence of the present invention is a composite composed of a combination in which a new absorption band appears on the long wavelength side of the main absorption band.

  Furthermore, in the general J-association formation found in solutions and the like, almost all molecules in the system form J-aggregates under the conditions where J-association is formed, and the absorption band of the monomer almost disappears. The absorption band of the J aggregate is observed as the main absorption band. On the other hand, in the formation of J aggregates on the clay sheet, only some of the molecules form J aggregates, so that the monomer absorption band remains the same and the long wavelength side of the monomer absorption band is increased. A new peak corresponding to the formation of J aggregates appears. Alternatively, wide absorption in which the absorption band of the monomer and the absorption band of the J aggregate are superposed is observed, and there is a case where a clear J aggregate does not appear.

  Therefore, in the present invention, the extent to which J aggregates are formed, that is, the amount of dye adsorbed on CEC is greatly involved.

  In addition, the present invention is clearly different in effect from the state in which it is dispersed in a dispersion medium, as in the example shown in Document 3 above, by forming it in a film shape. That is, FIG. 1 shows the two-photon absorption cross-sectional area (800 nm) when smectite, a clay mineral, is dispersed in dimethyl sulfoxide and MPPBT represented by the following chemical formula is absorbed, and when formed into a film in the present invention. The graph which measured the two-photon absorption amount per molecule is shown.

図１より、粘土に特定の化合物が吸着している場合、二光子吸収断面積は、ＣＥＣ比が４０％までは、溶液に分散した状態より膜状物の方が大きいことが分かる。

As can be seen from FIG. 1, when a specific compound is adsorbed on clay, the two-photon absorption cross section is larger in the film-like material than in the state dispersed in the solution until the CEC ratio is 40%.

  The reason is not necessarily clear, but it seems to be caused by the fact that the clay adsorbing the organic matter exists at an appropriate distance and J-associates beyond the clay particles.

  Examples are shown below.

Preparation of Inorganic-Organic Composites 60 ml of an aqueous suspension of synthetic saponite (0.2 g / l) was treated with ultrasonic waves for 30 minutes, and MPPBT in dimethyl sulfoxide solution (concentration varied to the required CEC ratio) ( 0.6 ml of 0.75 × 10-4-1 × 10 −3 mol / l) was added. This suspension was filtered through a membrane filter (cellulose mixed ester type) having a pore size of 0.1 μm, and the composite remaining on the filter was pressure-bonded to a glass substrate to obtain an inorganic-organic composite.
[Method for evaluating two-photon absorption cross section]
The evaluation of the two-photon absorption cross section of the compounds of the present invention is determined by M. Sheik-Bahae.
et.al., IEEE
The method described in J. Quantum Electronics 1990, 26, 760. was used as a reference. As a light source for measuring the two-photon absorption cross section, Ti: sapphire pulsed laser light (pulse width: 120 fs, repetition rate: 1 kHz, average output: 0.4 mW, peak power: 3.3 GW) passed through a regenerative amplifier is used. The two-photon absorption cross section was measured at a wavelength of 800 nm.

The two-photon absorption cross-section of the compounds of the present invention measured by the aforementioned methods, the results obtained in GM units ^{(1GM = 1 × 10 -50 cm} 4 s / photon) shown in Table 1. The two-photon absorption cross-sectional area of the compound before film formation is also shown.

These are graphs showing the two-photon absorption cross-section (800 nm) per molecule when a specific organic compound is adsorbed on clay to form a composite film and when dispersed in a medium.

Claims (5)

A substituted or unsubstituted electron-withdrawing aromatic that forms a chromophore in a dispersion medium of smectite dispersed in particles of 0.01 μm to several μm by dilutely dispersing in a solution and stirring vigorously 3-40% of the ion exchange capacity of the smectite by adding and stirring an organic compound in which a group and a substituted or unsubstituted aromatic group having an electron donating group are bonded via a conjugated group A method for producing a two-photon absorption film obtained by depositing an inorganic compound-organic compound complex having adsorbed with an organic compound in a thickness of 0.5 μm to 10 μm. The method for producing a two-photon absorption film according to claim 1, wherein the electron-attracting group is an aromatic group having at least one group selected from onium ion groups. The method for producing a two-photon absorption film according to claim 1 or 2, wherein the smectite is at least one selected from saponite, socolite, beidellite, hectorite, and montmorillonite. 4. The method for producing a two-photon absorption film according to claim 1, wherein the electron donating group is an aromatic group having an amino group, an alkoxy group, an alkylthio group, a hydroxyl group, a halogen atom, or an alkyl group. The inorganic compound-organic compound composite according to any one of claims 1 to 4, wherein the organic compound adsorbed on the smectite is at least one selected from a cyanine dye, a merocyanine dye, a hemicyanine dye, and a pyrylium dye. A method for producing a two-photon absorption film comprising a body.

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