JPH06345747A - 4-nitro-n-(1'-piperidinocarbonyl)aniline and non-linear optical material - Google Patents

Abstract

PURPOSE:To obtain a new compound useful as a nonlinear optical material becoming a nonlinear optical material having a high non-linear optical coefficient, having high nonlinear optical characteristics and excellent transparency in a visible region required as a wavelength converting material. CONSTITUTION:4-Nitro-N-(1'-piperidinocarbonyl)aniline. The compound is obtained by reacting 4-nitrophenyl isocyanate with piperidine. The compound may be used alone or as a composition dispersed or dissolved in a polymer compound. Since the compound contains a nitro group as an acceptor group and 1'-piperidinocarbonyl group as a donor group and these groups are conjugated with a benzene pi electron system, a large dipole moment is produced by electron change transfer in an excited state and the compound has high polarizability. Consequently, high optical nonlinearity is generated and absorption wavelength is transferred to a short wavelength side by the existence of carbonyl group in the donor to give a nonlinear optical material transparent in a blue region.

Description

Detailed Description of the Invention

[0001]

The present invention relates to the second harmonic generation (SH
G), harmonic generation such as third harmonic generation (THG),
The present invention relates to a novel 4-nitro-N- (1'-piperidinocarbonyl) aniline which can be used for an element such as an electro-optical switch and a nonlinear optical material using the same.

[0002]

2. Description of the Related Art In order to realize ultra-high speed and large capacity in information and communication, the role of a non-linear optical element for controlling the behavior of light such as light mixing, parametric oscillation and wavelength conversion has become important. Conventionally, as a nonlinear optical element, KT
Inorganic materials such as iOPO ₄ and KH ₂ PO ₄ have been used. However, these materials have a large nonlinear optical effect,
In terms of response speed and resistance to optical damage, it has not yet fully met the requirements for actual deviceization. On the other hand, organic materials having π-electrons that easily respond to light are widely researched because they are superior to inorganic materials in terms of magnitude of nonlinear optical effect, response speed, resistance to light damage, and the like. Regarding these achievements, for example, "Nonlinear Optical Properties of Organic Moleculars and Crystals" (Nonlinear Optical Properties o
f Organic Molecules and Crystals) vol.1 and vol.
2, DS Chemla, J. Zyss (ed. Academic Press, 1987). However, 800-
When the second harmonic generation is performed by using a semiconductor laser of 900 nm as a light source, a material that is transparent in the blue region of 400-450 nm and has a large nonlinear optical constant has not been found. Development is strongly demanded.

[0003]

SUMMARY OF THE INVENTION The present invention is a novel organic non-linear optical material having a large non-linear optical constant.
The present invention provides nitro-N- (1'-piperidinocarbonyl) aniline and a non-linear optical material using this compound.

[0004]

The present invention is based on the formula (1)

[Chemical 2] The present invention relates to 4-nitro-N- (1'-piperidinocarbonyl) aniline represented by, a non-linear optical material comprising this compound, and a non-linear optical material comprising a composition containing this compound.

4-nitro-N represented by the above formula (1)
-(1'-Piperidinocarbonyl) aniline is synthesized by reacting 4-nitrophenyl isocyanate with piperidine. For example, an equimolar or excess molar amount of piperidine is used with respect to 4-nitrophenyl isocyanate, and the mixture is heated in an amount of about 20 times to about 20 times the total weight of 4-nitrophenyl isocyanate and piperidine, if necessary. The compound can be obtained. The molar ratio of 4-nitrophenyl isocyanate / piperidine is preferably in the range of 1.0 to 1.8. Preferred solvents include tetrahydrofuran, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexane, 1,
4-dioxane, cyclohexanone, toluene, benzene, chloroform can be mentioned. In general, the reaction temperature is preferably room temperature to 150 ° C. The reaction may be performed in ice water or a water bath for the purpose of controlling the reaction temperature.

The nonlinear optical material according to the present invention is the above-mentioned 4
-Nitro-N- (1'-piperidinocarbonyl) aniline may be used alone or as a composition in which this compound is dispersed or dissolved in a polymer compound. Examples of the polymer compound include methyl (meth) acrylate (indicating methacrylate or acrylate; the same applies hereinafter), ethyl (meth) acrylate, n-butyl (meth) acrylate, cyclohexyl (meth) acrylate, (meth) acrylic acid, Homopolymers, copolymers or terpolymers, polyesters, polyamides, polyamic acids, polyurethanes, polycarbonates, cellulose esters, polyethers, polyimides of monomers such as styrene, vinyltoluene, divinylbenzene, vinyl chloride, β-hydroxyethyl (meth) acrylate, etc. Etc. are used. A compound represented by the formula (1) and a corresponding monomer may be mixed and then polymerized by the action of heat to form a composition. The polymer compound and the compound represented by the formula (1) may be appropriately used. The composition may be obtained by dissolving and mixing with a suitable solvent and then removing the solvent. In the former case, the non-linear optical performance can be improved by performing poling during the polymerization or by performing poling after obtaining the composition for both the former and the latter. Alternatively, the molecular orientation state was controlled by heating the compound represented by the above formula (1) to a temperature equal to or higher than the melting point in the presence of a direct current electric field to melt it, and then slowly cooling or rapidly cooling while maintaining the electric field. It is also possible to obtain a single crystal or molecular glass having high nonlinear optical performance. Also, "Applied Physics Letter"
vol.56, p2610 (1990), the photocrosslinkable resin and the compound represented by the formula (1) are dissolved and mixed with an appropriate solvent, and then the solvent is removed and heated. However, it is also possible to obtain a nonlinear optical material in which the molecular orientation state is controlled by simultaneously performing poling and light irradiation.

The above-mentioned non-linear optical materials can be used in the form of bulk crystals independently, or in fiber type, slab type, plane type,
It can be used as part of a waveguide type nonlinear optical element such as a channel type. Non-linear optical elements using the above-mentioned non-linear optical material include wavelength conversion elements using second harmonic generation, sum frequency generation or optical parametric oscillation, phase modulation elements using electro-optic effect, polarization plane modulation elements, and the like. .

[0008]

The compound of the present invention has a nitro group as an acceptor group and a 1'-piperidinocarbonylamino group as a donor group, and these compounds are conjugated with the benzene π electron system. The movement causes a large dipole moment and has a high polarizability, which causes a high optical nonlinearity. Furthermore, the presence of the carbonyl group in the donor group causes the absorption wavelength to move to the short wavelength side, which is a transparent nonlinear optical in the blue region. The material is obtained.

[0009]

EXAMPLES The present invention will be described with reference to examples. Synthesis of 4-nitro-N- (1'-piperidinocarbonyl) aniline In a 100 ml round-bottomed flask, 1.64 g (10 mmol) of 4-nitrophenyl isocyanate was dissolved in 30 g of tetrahydrofuran, and the solution was moved to an ice bath. 0.89 g (10.5 mmol) of piperidine was added dropwise. After stirring for about 2 hours, the solution was returned to room temperature and recrystallized with n-hexane to obtain a white precipitate. The precipitate was filtered and washed well with methanol. Yield about 2.32
It was g (93%). The structure of the product was confirmed by ¹ H-nmr and UV-visible absorption spectrum. The melting point was measured by DTA. The ultraviolet-visible absorption spectrum in ethanol solution of this material in Figure 1, a heavy chloroform solution ¹ H-
The nmr spectrum is shown in FIG. The chemical shift values of typical peaks are summarized in Table 1. The structure of the compound was determined by ¹ H-nmr and UV-visible absorption spectrum.

[0010]

[Chemical 3]

[Table 1]

Examples, Comparative Examples The second harmonic intensity (SH intensity) of 4-nitro-N- (1'-piperidinocarbonyl) aniline obtained in Example 1.
Was measured by the powder method. The outline of the powder method is “Journal of Applied Physics”.
lied Physics) vol. 36, pages 3798 to 3813 (1963). A sample crushed to a particle size of 50 to 150 μm is sandwiched between non-fluorescent slide glass (made by Matsunami Glass), and a pulse Nd: YAG made by Spectro Laser System Co., Ltd.
Laser (SL303 type, maximum output 850 mJ, half width 1
5ns, output per pulse 60MW, beam diameter 9.5
mm, wavelength 1.064 μm, repetition frequency 10 Hz)
It was irradiated with light. The intensity of the generated second harmonic at 532 nm was measured by a photomultiplier tube through an infrared filter and a UV filter. Table 2 shows the absorption edges on the longest wavelength side observed in the second harmonic intensity and the UV-visible absorption spectrum. For comparison, Table 2 shows urea and 2-methyl-4-nitroaniline (MN), which are typical organic nonlinear optical materials.
The value of A) is shown. Table 2 also shows these melting points.

[0012]

[Table 2]

[0013]

INDUSTRIAL APPLICABILITY 4-Nitro-N- (1'-piperidinocarbonyl) aniline has high non-linear optical properties and excellent transparency in the visible region which is required as a wavelength conversion material. A nonlinear optical material having a high constant can be obtained.

[Brief description of drawings]

FIG. 1 is an ultraviolet-visible absorption spectrum of an ethanol solution of 4-nitro-N- (1′-piperidinocarbonyl) aniline obtained in Example.

FIG. 2 ¹ H of a solution of 4-nitro-N- (1′-piperidinocarbonyl) aniline obtained in Example in deuterated chloroform.
-Nmr spectrum.

Claims (3)

[Claims] 1. A 4-nitro-N represented by the following formula (1):
-(1'-piperidinocarbonyl) aniline. [Chemical 1] 2. A non-linear optical material comprising 4-nitro-N- (1'-piperidinocarbonyl) aniline. 3. A nonlinear optical material comprising a composition containing 4-nitro-N- (1'-piperidinocarbonyl) aniline.