KR0163122B1 - Main chain polymer having nonlinear optical property - Google Patents

Abstract

The present invention is a wholly aromatic polyester of formula (1) obtained from 2,5-di {1- [N- (4-nitrophenyl)-(L) -prolineoxy] alkyleneoxy} terephthalic acid exhibiting excellent nonlinear optical properties To provide.

[Formula 1]

In Chemical Formula 1 Is a chromophore (nonlinear optical characteristic group), and is represented as in Chemical Formula 2, and the degree of polymerization r is an integer of 3 to 300.

[Formula 2]

R ₁ in Formula 2 is -O- (CH ₂ ) _q -O- (q is an integer of 1 to 20), -S- (CH ₂ ) _m -S- (m is an integer of 1 to 20), (n is an integer from 1 to 5) or (p is an integer of 1 to 6), R ₂ is CF ₃ , NO ₂ , CN, And SO ₂ R, and R is an alkyl group having 1 to 20 carbon atoms.

In addition, in Chemical Formula 1, Z is a co-unit,

One) X is H, Cl, Br, CH ₃ , , , (CH ₂ ) _k -CH ₃ (k is an integer from 1 to 9), , Benzene derivatives such as 1,2-, 1,3- and 1,4- which are substituents such as

2) : 1,1'-, 2,2'-, 3,3'-, 4,4'-, 1,4'-, 1,3'-, 1,2'-, 2,3'-, 2 Biphenyl isomers such as, 4'-, 3,4'-,

3) : 1,4-. Naphthalene isomers such as 1,5-, 1,6-, 1,7-, 2,3-, 2,5-, 2,6-, 2,7-, or

4) X is O, CH ₂ , , SO ₂ , S, Such as bisphenol isomers, and the like.

Description

Main chain polymer with nonlinear optical properties

[Industrial use]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to new polymers having nonlinear optical properties which are superior to conventional ones as nonlinear optical materials used for optical information processing, optical communication, and the like.

[Prior art]

With the recent invention of lasers, interest in nonlinear optical materials has increased due to advantages such as high power, monochromaticity, and phase matching of lasers, which facilitate the investigation of nonlinear optical properties in various materials. Materials with large nonlinear optical coefficients discovered by the use of lasers are widely used as the core components of laser devices through the conversion of laser wavelengths or energy conversion. Optical devices based on these nonlinear optical materials are used in the next generation industry. Recently, research is being conducted by various companies and research institutes because they can be used as core devices in various fields such as optical communication, optical computer, and optical memory devices that will lead the revolution.

All non-linear optical materials currently in use are inorganic single crystals, which are 1) hard to obtain crystals, 2) low laser threshold damage, 3) high dielectric constant, and slow response time when compared to organic crystals or polymers. The disadvantages are very high processing temperatures. Therefore, in recent years, researches on organic crystals and polymers have been actively conducted to compensate for their shortcomings. In particular, polymers have no difficulty in growing single crystals, are easy to process, and can be processed into thin thin film materials. It has been actively studied. These organic polymers (polymers) are very important in that various optical devices can be manufactured by directly connecting with semiconductor technologies due to the maturation of semiconductor technology based on existing silicon.

The largest nonlinear optical effect that organic nonlinear optical polymers can exhibit is the secondary nonlinear optical effect, and the optical or optoelectronic devices that can be manufactured by using the secondary nonlinear optical effect are the light that converts the wavelength or phase of the laser. The fabrication of optical memory devices using modulators, switches, couplers, and modulated wavelengths of light enables the fabrication of devices with much higher storage capacities than current magnetic disks. In addition, when applied to the optical communication or optical computer field can not only deliver a much larger amount of information than now, but also improve the processing speed of the information can not be compared.

Due to the above advantages, many researches on secondary nonlinear optical materials for organic polymers have been conducted. These studies are mainly related to the host-guest system in which the nonlinear optical properties are dispersed in the polymer system. Nonlinear optical properties can be classified as functionalized systems in which the side chains of the polymer or the main chain are bonded. In the case of the first mentioned host-guest system, the nonlinear optical properties generally have a lack of mixing with the polymer, which limits the inclusion of them in the polymer system, and they can scatter light due to crystallization in the polymer system. Many researches have been conducted in the early stages because of various disadvantages such as sublimation at high temperatures. However, most of the latter studies have been actively conducted on covalent bond systems.

However, the inorganic single crystal of these conventional techniques has the disadvantages mentioned above, and in the case of the conventional organic polymer materials described in, for example, EP 243,860, etc., one chromophore is included per repeating unit so that the nonlinear optical The coefficients are not optimized and the main chain of the polymer is an aliphatic flexible chain, which causes the nonlinear optical properties of the nonlinear optical properties caused by polling to be distorted relatively easily even at low temperature. The absorption wavelength of the TCNQ chromophore used as the characterizer is too high, which makes it difficult to investigate the secondary nonlinear optical effect.

Accordingly, an object of the present invention is to provide a new nonlinear optical polymer exhibiting excellent nonlinear optical properties by solving the disadvantages of the inorganic single crystal and the conventional organic polymer material.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a polymer represented by the following formula (1).

In Chemical Formula 1 Is a chromophore (nonlinear optical characteristic group), and is represented as in Chemical Formula 2, and the degree of polymerization r is an integer of 3 to 300.

R ₁ in Formula 2 is -O- (CH ₂ ) _q -O- (q is an integer of 1 to 20), -S- (CH ₂ ) _m -S- (m is an integer of 1 to 20), (n is an integer from 1 to 5) or (p is an integer of 1 to 6), R ₂ is CF ₃ , NO ₂ , CN, And SO ₂ R, and R is an alkyl group having 1 to 20 carbon atoms.

In addition, in Chemical Formula 1, Z is a co-unit,

One) X is H, Cl, Br, CH ₃ , , , (CH ₂ ) _k -CH ₃ (k is an integer from 1 to 9), , Benzene derivatives substituted at positions such as 1,2-, 1,3-, 1,4- and the like

2) : 1,1'-, 2,2'-, 3,3'-, 4,4'-, 1,4'-, 1,3'-, 1,2'-, 2,3'-, 2 A biphenyl isomer substituted at a position such as, 4'-, 3,4'-,

3) : 1,4-. Naphthalene isomers substituted at the positions 1,5-, 1,6-, 1,7-, 2,3-, 2,5-, 2,6-, 2,7-

4) X is O, CH ₂ , , SO ₂ , S, ,

Such as bisphenol isomers are used.

Although the polymer represented by Chemical Formula 1 according to the present invention has a very high chromophore concentration, it is possible to prepare a film having high optical properties due to its high solubility in organic solvents. In addition, the polymers according to the invention are characterized by very large nonlinear optical coefficients. This can be easily understood from the fact that the second order nonlinear optical coefficient d ₃₃ (χ ⁽²⁾ = 2d) is directly proportional to the concentration of the chromophore. The nonlinear optical coefficient d ₃₃ of the polymer according to the present invention exhibits a value of about 10 ⁻⁶ esu, which is the largest nonlinear optical coefficient of nonlinear optical polymers known to date. The reason why the polymer according to the present invention has such a large nonlinear optical coefficient is that the polymer according to the present invention has a high concentration of intramolecular chromophores and the structure of the main chain as described above. It can be easily understood from the fact that the monomer used as the chromophore is oriented in a form close to the two-dimensional structure rather than a full three-dimensional structure such as methyl methacrylate)) and has a very large second order nonlinear optical coefficient. The polymer according to the present invention having such advantages can be used for the conversion of the wavelength or energy of the laser, and these polymers are very well dissolved in organic solvents, making it easy to produce a thin film-like material, and the phase change of the laser It can be used in various optical materials such as modulator, switch, coupler.

The chromophore compound used in the present invention can be easily prepared by the following method as described in Korean Patent Application No. 95-13864. The preparation method thereof will be described with reference to 2,5-di {1- [N- (4-nitrophenyl)-(L) -prolineoxy] hexamethyleneoxy} terephthalic acid as follows.

N- (4-nitrophenyl)-(L) by reacting L-prolinol (III) with 1-fluoro-4-nitrobenzene (II) -Prolinol (IV) is obtained, and N- (4-nitrophenyl)-(L) -prolinol (IV) is reacted with 1,6-dibromohexane to give 1- [N- (4-nitrophenyl)-(L) -prolinoxy] -6-bromohexane (V) was obtained, and this 1- [N- (4-nitrophenyl)-(L) -proline Oxy] -6-bromohexane (V) was reacted with diethyl 2,5-dihydroxy terephthalate to diethyl 2,5-di {1- [N- (4 -Nitrophenyl)-(L) -prolineoxy] hexamethyleneoxy} terephthalate (VI) to give diethyl 2,5-di {1- [N- (4-nitrophenyl)-(L) -Prolineoxy] hexamethyleneoxy} terephthalate (VI) was refluxed in a basic solution to give 2,5-di {1- [N- (4-nitrophenyl)-(L) -prolineoxy] hexamethyleneoxy} terephthalic acid ( terephthalic acid) is obtained.

This is briefly shown in the scheme below.

R in the above scheme And q is an integer from 1 to 20.

The polymer (VIII) according to the present invention is easily produced from the compound (VIII) produced by the above method according to the following reaction route.

R in the above scheme (q is an integer of 1 to 20), and r is an integer of 3 to 300 as the degree of polymerization.

EXAMPLE

The following presents a preferred embodiment to aid the understanding of the present invention. However, the following examples are merely provided to more easily understand the present invention, and the present invention is not limited to the following examples.

Example 1

Synthesis of N- (4-nitrophenyl)-(L) -prolinol (Scheme 1)

Under a stream of nitrogen, 25 g (0.247 mol) of L-prolinol, 25 g of potassium carbonate and 25 ml of purified dimethylformamide were added to a three necked flask, and 33 g (0.234 mol) of 1-fluoro-4-nitrobenzene was added to the solution. Slowly added dropwise. After the addition, the reaction was reacted at 50 ° C. for 24 hours. After the reaction was cooled, the mixture was poured into distilled water to obtain a precipitate. The precipitate obtained was filtered and washed twice with distilled water. The product was dried in a vacuum oven at room temperature. The yield of dried product was 95% (49.1 g) and the melting point was 117 ° C.

IR (cm ⁻¹ ): 3450 (OH, str.), 3140 (Ar. CH str.), 2950 (ali. CH str.), 1100-1130 (CO str.)

¹ H-NMR (CDCl ₃ ), ppm: 2.0 (brs. 1 H, -OH), 2.0-2.3 (m, 4H, -CH _2- ), 3.2-3.8 (m, 4H, -N-CH ₂ , O -CH ₂ ), 3.9-4.2 (quen. 1H, -N-CH), 6.6 (d, 2H, meta H from NO ₂ ), 8.1 (d, 2H, ortho H from NO ₂ )

Example 2

Synthesis of 1- [N- (4-nitrophenyl)-(L) -prolinol] -6-bromohexane (Scheme 2)

Synthesis of α-N- (nitrophenyl)-(L) -prolineoxy-ω-bromoalkane according to the present invention was carried out according to the following method. Representatively, the case of 1- [N- (4-nitrophenyl)-(L) -prolinol] -6-bromohexane is described as an example. 5 g (0.0226 mol) of N- (4-nitrophenyl)-(L) -prolinol synthesized in Example 1 was dissolved in 50 ml of purified THF, and then 2.7 g (0.113 mol) of NaH was added thereto for 30 minutes. Stirred. When the color of the first solution turned yellow from yellow to salt formation, 38.3 g (0.157 mol) of 1,6-dibromohexane was added thereto, followed by reaction at 60 to 70 ° C. for 12 hours. After the reaction, the solution was confirmed by TLC. As a result, N- (4-nitrophenyl)-(L) -prolinol disappeared completely. After completion of the reaction, the solution was filtered, and the filtrate was distilled under reduced pressure to remove THF and excess 1,6-dibromohexane. The remaining reaction product was separated by column chromatography using a mixed solvent of hexane and ethyl acetate (3/1 = V / V) to obtain a pure reaction product.

IR (cm ⁻¹ ): 3124 (Ar. CH str.), 2800-3000 (ali. CH str.), 1600 (Ar, C = C str.), 1512 (NO str.), 1307 (CO str. )

¹ H-NMR (CDCl ₃ ), ppm: 1.5-2.3 (m, 12H, -CH _2- ), 3.2-3.6 (m, 8H, -N-CH ₂ , O-CH ₂ , Br-H), 3.9 -4.2 (quen. 1H, -N-CH), 6.5 (d, 2H, meta H from NO ₂ ), 8.2 (d, 2H, ortho H from NO ₂ )

Example 3

Synthesis of diethyl 2,5-di {1- [N- (4-nitrophenyl)-(L) -prolineoxy] hexyleneoxy} terephthalate (Scheme 3)

All diethyl 2,5-di {1- [N- (4-nitrophenyl)-(L) -prolineoxy] alkyleneoxy} terephthalates according to the invention were synthesized in the same way, here In particular, the compound whose q = 6 is described.

In a 250 mL three neck flask, 5 g (0.0197 mol) of diethyl 2,5-dihydroxy terephthalate and 5 g of K ₂ CO ₃ were dissolved in 20 mL of DMF, followed by stirring for 30 minutes. 22.4 g (0.0591 mol) of 1- [N- (4-nitrophenyl)-(L) -prolineoxy] -6-bromohexane was added dropwise to 10 ml of purified THF. The reaction solution was heated to 50 ° C. and reacted for 24 hours. After the reaction, the solution was filtered to remove K ₂ CO ₃ , and DMF was distilled under vacuum and poured into distilled water to obtain a precipitate. The light brown product was recrystallized in a mixed solvent of DMF / EtOH = 1/4 (V / V) to give a yellow solid product. The yield was 90% (15.27 g), the melting point was 63 ℃. The structure of the final product was confirmed by IR and NMR spectra, it was confirmed that the pure compound was obtained using TLC.

IR (cm ⁻¹ ): 2800-3000 (ali. CH str.), 1730 (C═O str.), 1620 (Ar. C═C str.), 1512 (NO str.), 1320 (CO str. )

¹ H-NMR (CDCl ₃ ), ppm: 1.3-1.4 (t, 6H, CH ₃ ), 1.7-2.3 (m, 28H, -CH _2- ), 3.2-3.6 (m, 12H, -N-CH ₂ , O-CH ₂ ), 3.9-4.2 (m, 6H, COOCH ₂ , -N-CH), 4.3-4.5 (4H, Ph-O-CH ₂ ), 6.6 (d, 4H, meta H from NO ₂ ) , 8.1 (d, 2H, ortho H from NO ₂ )

Example 4

Synthesis of 2,5-di {1- [N- (4-nitrophenyl)-(L) -prolineoxy] hexyleneoxy} terephthalic acid (Scheme 4)

60 ml of ethanol was used for 47.62 g (0.058 mol) of diethyl 2,5-di {1- [N- (4-nitrophenyl)-(L) -prolineoxy] hexyleneoxy} terephthalate prepared in Example 3. Boiled by addition. 3.25 g (0.058 mol) of KOH was added thereto, dissolved in 30 ml of ethanol, and refluxed for 3 hours. After completion of the reaction, ethanol was removed by distillation under reduced pressure, and a light brown viscous product was dissolved in distilled water and acidified with 2N HCl. CH ₂ Cl ₂ was added to the solution to extract the product, to obtain a yellow solid product. The solid product thus obtained was recrystallized from ethanol to give a pure product. The yield was 90% (31.81 g). The structure of the final product was confirmed by IR and NMR spectra, it was confirmed that the pure compound was obtained using TLC.

IR (cm ⁻¹ ): 2400-3600 (OH str.), 1730 (C═O str.), 1620 (Ar. C = C str.), 1512 (NO str.), 1320 (CO str.)

¹ H-NMR (CDCl ₃ ), ppm: 1.7-2.3 (m, 28H, -CH _2- ), 3.2-3.6 (m, 12H, -N-CH ₂ , O-CH ₂ ), 3.4-4.3 (m , 6H, COOCH ₂ , -N-CH ₂ ), 4.4-4.6 (4H, Ph-O-CH ₂ ), 6.67 (d, 4H, meta H from NO ₂ ), 7.44 (s, 2H, Ar), 8.3 (d, 2H, ortho H from NO ₂ )

Example 5

Synthesis of Polymer (Scheme 5)

A 250 mL four-necked round bottom flask was equipped with a stirrer, and then 1.16 mL (0.006 mol) of SOCl ₂ was added to an ice bath. Pyridine 23g (0.003mol) was added dropwise thereto and stirred for 30 minutes. 1.21 g of diethyl 2,5-di {1- [N- (4-nitrophenyl)-(L) -prolineoxy] hexyleneoxy} terephthalic acid in a separate flask when the temperature of the solution reached 2 to 3 ° C 0.0015 mol) was dissolved in 10 ml of pyridine and slowly added dropwise. After dropping the ice bath was removed and stirred for 30 minutes at room temperature. 0.17 g (0.0015 mol) of hydroquinone was added to the solution and reacted at 80 ° C. for 24 hours under a nitrogen stream. After completion of the reaction, the reaction solution was poured into excess methanol to obtain a precipitate. The precipitate was filtered off, washed three times with methanol and distilled water, and dried in a vacuum oven at 60 ° C. The yield of the polymer was 92% (1.21 g).

IR (cm ⁻¹ ): 3070 (Ar. CH str.), 2800-2950 (ali. CH str.), 1730 (C═O str.), 1620 (Ar. C = C str.), 1522 (NO str.), 1310 (CO str.)

¹ H-NMR (CDCl ₃ ), ppm: 1.6-2.2 (m, 24H, -CH _2- ), 3.1-3.7 (m, 12H, -N-CH ₂ , O-CH ₂ ), 4.1-4.2 (m , 2H, N-CH ₂ ), 4.2-4.4 (t, 4H, Ph-O-CH ₂ ), 6.6 (d, 4H, meta H from NO ₂ ), 7.34 (s, 2H, Ar.), 7.6 ( ms, 2H, TPA), 8.2 (d, 2H, ortho H from NO ₂ )

Example 6

Synthesis of Polymer

1.21 g (0.0015 mol) of diethyl 2,5-di {1- [N- (4-nitrophenyl)-(L) -prolineoxy] hexyleneoxy} terephthalic acid and excess in a 250 ml three-necked flask under nitrogen stream After adding SOCl ₂ and refluxing at 80 ° C. for 4 hours, excess SOCl was removed to obtain a yellow acid chloride. The acid chloride was dissolved in 20 ml of tetrachloroethane, and then 0.17 g (0.0015 mol) of hydroquinone was dissolved in 20 ml of tetrachloroethane and 10 ml of pyridine, and reacted at room temperature for 2 hours and at 80 ° C for 4 to 10 hours. After completion of the reaction, the reaction solution was poured into excess methanol to obtain a precipitate. The precipitate was filtered off, washed three times with methanol and distilled water, and dried in a vacuum oven at 60 ° C.

Example 7

Preparation of Thin Films

5 to 15% by weight of the polymer prepared in Example 6 was dissolved in an organic solvent, impurities were filtered through a scanning filter, and then a thin thin film was formed using a rotary coating machine, and then dried in a vacuum oven. The film was polled using a corona polling apparatus to evaluate the nonlinear optical properties.

In order to investigate the nonlinear optical properties of the polymer prepared by the method of Examples 5 to 6, first, the linear optical properties were investigated. The maximum absorption wavelength in the ultraviolet-visible absorption spectrum of the polymer was 400 nm. The ultraviolet-visible light absorption band of such a polymer does not overlap the fundamental wave (1064 nm) and the second harmonic wave (532 nm) of the Nd-YAG laser to be used for the measurement of secondary nonlinear optical properties. The measurement of the secondary nonlinear optical properties was measured according to the Maker-fringe method using an Nd-YAG laser. A modification was used as the reference material and the absolute value of the nonlinear coefficients of the polymers was evaluated as the intensity of the nonlinear optical properties relative to the reference material. The nonlinear optical coefficient of the polymer according to the invention thus evaluated showed about 10 ⁻⁶ esu. This value is the largest of the nonlinear optical coefficients of the polymers reported so far.

It is possible to provide a new nonlinear optical polymer having a large nonlinear optical coefficient and exhibiting excellent nonlinear optical properties.

Claims (1)

A polymer represented by the following formula (1). [Formula 1] In Chemical Formula 1 Is a chromophore (nonlinear optical characteristic group), and is represented as in Chemical Formula 2, and the degree of polymerization r is an integer of 3 to 300. [Formula 2] R ₁ in Formula 2 is -O- (CH ₂ ) _q -O- (q is an integer of 1 to 20), -S- (CH ₂ ) _m -S- (m is an integer of 1 to 20), (n is an integer from 1 to 5) or (p is an integer of 1 to 6), R ₂ is CF ₃ , NO ₂ , CN, And SO ₂ R, and R is an alkyl group having 1 to 20 carbon atoms. In addition, in Chemical Formula 1, Z is a co-unit, One) X is H, Cl, Br, CH ₃ , , , (CH ₂ ) _k -CH ₃ (k is an integer from 1 to 9), , Benzene derivatives of 1,2-, 1,3- and 1,4- which are substituents of 2) : 1,1'-, 2,2'-, 3,3'-, 4,4'-, 1,4'-, 1,3'-, 1,2'-, 2,3'-, 2 , 4'-, 3,4'- biphenyl isomer, 3) : 1,4-. Naphthalene isomers of 1,5-, 1,6-, 1,7-, 2,3-, 2,5-, 2,6-, 2,7- and 4) X is O, CH ₂ , , SO ₂ , S, Phosphorus bisphenol isomers.