JP3837463B2 - Second-order nonlinear optical material - Google Patents

Description

（式中のＸは炭素数１〜４のジアルキルアミノ基又は炭素数１〜４のアルキルチオ基、Ｙはニトロ基又はシアノ基、ｎは１〜３の整数である）で表わされる芳香族オリゴエステル類から成る二次非線形光学材料を提供するものである。
【０００９】
【発明の実施の形態】
本発明の芳香族エステル類は、前記一般式（Ｉ）で表わされる構造を有するものである。この一般式（Ｉ）において、Ｘで示される炭素数１〜４のジアルキルシアノ基及び炭素数１〜４のアルキルチオ基中のアルキル基としては、例えばメチル基、エチル基、ｎ‐プロピル基、イソプロピル基、ｎ‐ブチル基、イソブチル基、ｓｅｃ‐ブチル基、ｔｅｒｔ‐ブチル基などが挙げられるが、これらの中で、二次非線形光学特性の面から、特にメチル基が好ましい。一方、Ｙはニトロ基又はシアノ基である。ｎは大きいほど二次非線形光学特性が向上するが、ｎが５以上のものは製造が非常に煩雑となり、実用的でないので１〜３の範囲で選ばれる。
【００１０】
この一般式（Ｉ）で表わされる芳香族オリゴエステル類としては、光学的透明性が良好で、かつ二次非線形光学特性に優れる点で、特に以下の化学構造をもつ４‐ジメチルアミノ安息香酸４‐シアノフェニルエステル（以下ＡｒＥＳ２−Ｎ／ＣＮと略記する）、４‐（４′‐ジメチルアミノフェニルカルボニルオキシ）安息香酸４‐シアノフェニルエステル（以下ＡｒＥＳ３−Ｎ／ＣＮと略記する）、４‐ジアルキルアミノ安息香酸４‐ニトロフェニルエステル（以下ＡｒＥＳ２−Ｎ／ＮＯ₂と略記する）、４‐メチルチオ安息香酸４‐シアノフェニルエステル（以下ＡｒＥＳ２−Ｓ／ＣＮと略記する）、４‐（４′‐メチルチオフェニルカルボニルオキシ）安息香酸４‐シアノエステル（以下ＡｒＥＳ３−Ｓ／ＣＮと略記する）が好適である。
【００１１】
前記一般式（Ｉ）で表わされるエステル類は、例えば反応式
【化２】

（式中のＨａｌはハロゲン原子、Ｘ、Ｙ及びｎは前記と同じ意味をもつ）に従い、
【化３】

（式中のＸ、Ｈａｌ及びｎは前記と同じ意味をもつ）で表わされる芳香族カルボン酸ハロゲン化物と、一般式
【化４】

（式中のＹは前記と同じ意味をもつ）で表わされるｐ‐置換フェノールとをハロゲン化水素捕捉剤の存在下で反応させるか、あるいは反応式
【化５】

（式中のｎ′は１又は２の整数、Ｘ、Ｙ及びＨａｌは前記と同じ意味をもつ）に従い、一般式
【化６】

（式中のＸ及びＨａｌは前記と同じ意味をもつ）で表わされるｐ‐置換安息香酸ハロゲン化物と、
【化７】

（式中のＹ及びｎ′は前記と同じ意味をもつ）で表わされるｐ‐ヒドロキシ安息香酸誘導体とを、ハロゲン化水素捕捉剤の存在下で反応させることによって製造することができる。
【００１２】
この反応の原料化合物として用いられる一般式（ＩＩ）又は（ＩＶ）で表わされる化合物中のＨａｌとしては、フッ素原子、塩素原子、臭素原子及びヨウ素原子を挙げることができる。また、この反応において用いられるハロゲン化水素捕捉剤としては、トリメチルアミン、トリエチルアミン、ピリジンなどの第三アミンが好ましいが、その他の有機塩基、無機塩基を用いることもできる。
これらの反応は、アセトン、メチルエチルケトン、ジエチルエーテル、酢酸エチル、テトラヒドロフラン、ジメチルホルムアミド、ジエチルスルホキシド、シクロヘキサンなどの不活性溶媒中で行うのが有利である。
【００１３】
他方、この反応の原料化合物として用いられる（ＩＩＩ）又は（Ｖ）で表わされる化合物の代りに、その水酸基のアルカリ金属塩すなわちフェノラートを用いると、ハロゲン化水素捕捉剤を存在させなくても所望の反応を行わせることができる。
【００１４】
これらの反応における原料化合物（ＩＩ）と（ＩＩＩ）又は（ＩＶ）と（Ｖ）とは、実質上化学量論的量で用いられるが、所望によっては一方の原料化合物を過剰に用いることもできる。また、これらの反応は、室温下、又は氷冷下で一方の原料化合物を含む溶媒中に他方の原料化合物を少しずつ添加し、かきまぜながら行われるが、所望ならば加温して反応を促進することもできる。反応時間としては、通常１〜３０時間の範囲が選ばれる。このようにして得た反応混合物を常法に従って水洗し、有機層を分層し、これから溶媒を除去すれば、目的とする本発明化合物が白色ないし淡かっ色の結晶として得られる。
【００１５】
なお、前記一般式（Ｖ）で表わされるｐ‐ヒドロキシ安息香酸誘導体は、例えば前記一般式（ＩＩＩ）のｐ‐置換フェノールと一般式
【化８】

（式中のＲは低級アルキル基であり、Ｈａｌ及びｎ′は前記と同じ意味をもつ）で表わされる酸無水物とをアセトンのような溶媒中、トリエチルアミンのようなハロゲン化水素捕捉剤の存在下で反応させて、一般式
【化９】

（式中のＲは低級アルキル基、Ｙ及びｎ′は前記と同じ意味をもつ）で表わされる化合物を製造し、次いでこれをアセトンのような溶媒中で塩基触媒の存在下、加水分解することによって製造することができる。
【００１６】
このようにして得られる前記一般式（Ｉ）の本発明化合物は光学的透明性が良好であるとともに、優れた二次非線形光学特性を有する新規化合物である。
この芳香族エステル類を分散させた厚さ約５０００Åのポリメチルメタクリレート薄膜（芳香族エステル類の含有量１０重量％）の二次非線形光学特性は、最適ポーリング温度が６０〜９０℃の範囲に存在し、またその温度でポーリング処理した後の二次非線形光学係数ｄ₃₃値が３×１０^-9〜４×１０^-9ｅｓｕである。
【００１７】
【実施例】
次に、本発明を実施例によりさらに詳細に説明する。
【００１８】
参考例１
４‐ジメチルアミノ安息香酸１．６５ｇ（１０．０ミリモル）に塩化チオニル１８ｍｌ（２５４ミリモル）を徐々に滴下したのち、１時間かきまぜて反応させた。反応終了後、過剰の塩化チオニルを留去し、残留物にアセトン２０ｍｌを加えて溶解することにより、４‐ジメチルアミノベンゾイルクロリドのアセトン溶液を調製した。別に４‐シアノフェノール１．１９ｇ（１０．０ミリモル）と、トリエチルアミン１４．０ｍｌ（１０１ミリモル）と、アセトン３０ｍｌとを混合し、これを前記の４‐ジメチルアミノベンゾイルクロリドのアセトン溶液中に氷冷下で滴下する。滴下終了後、氷浴中で１夜かきまぜて反応させたのち、反応混合物を５重量％Ｋ₂ＣＯ₃水溶液中に注加し、生成した沈殿をろ取した。次いで、得られた固体を、アセトン／水混合溶媒で２回再結晶したのち、室温で１夜減圧乾燥することにより、式
【化１０】

で示されるＡｒＥＳ２−Ｎ／ＣＮ１．１７ｇ（収率４３．９％）を融点１５２．０〜１５３．５℃の白色固体として得た。このものの４００ＭＨｚで行った¹Ｈ−ＮＭＲ（ＣＤＣｌ₃）による構造解析の結果を次に示す。
δ＝３．１０［ｓ，６Ｈ，（ＣＨ₃）₂Ｎ−］、６．７４（ｄ，Ｊ＝８．８Ｈｚ，２Ｈ，ａの芳香族プロトン）、７．３５（ｄ，Ｊ＝８．８Ｈｚ，２Ｈ，ｃの芳香族プロトン）、７．７２（ｄ，Ｊ＝８．８Ｈｚ，２Ｈ，ｄの芳香族プロトン）、８．０４（ｄ，Ｊ＝８．８Ｈｚ，２Ｈ，ｂの芳香族プロトン）。
【００１９】
参考例２
４‐ジメチルアミノ安息香酸０．８３ｇ（５．００ミリモル）に塩化チオニル９．０ｍｌ（１２７ミリモル）を徐々に滴下したのち、１時間かきまぜて反応させた。反応終了後、過剰の塩化チオニルを留去し、残留物にアセトン４０ｍｌ及びトリエチルアミン３．０ｍｌを加え、アセトン溶液を調製した。別に４‐ヒドロキシ安息香酸４‐シアノフェニルエステル１．２０ｇ（５．００ミリモル）とトリエチルアミン４．０ｍｌ（合計量５０．０ミリモル）と、アセトン２０ｍｌとの混合溶液を調製し、氷冷下に前記アセトン溶液中に滴下した。滴下終了後、氷浴下に１夜かきまぜて反応させ、次いで反応混合物を５重量％ＮａＨＣＯ₃水溶液中へ注加した。沈殿をろ別し、アセトン／水混合溶媒で２回再結晶したのち、室温で１夜減圧乾燥した。このようにして、式
【化１１】

で示されるＡｒＥＳ３−Ｎ／ＣＮ０．８１ｇ（収率４１．９％）を融点１９０℃以上の白色固体として得た。このものの¹Ｈ−ＮＭＲ（ＣＤＣｌ₃）による構造解析の結果を次に示す。
δ＝３．１０［ｓ，６Ｈ，（ＣＨ₃）₂Ｎ−］、６．７１（ｄ，Ｊ＝８．８Ｈｚ，２Ｈ，ａの芳香族プロトン）、７．３８（ｍ，４Ｈ，ｃ及びｅの芳香族プロトン）、７．７６（ｄ，Ｊ＝８．８Ｈｚ，２Ｈ，ｆの芳香族プロトン）、８．０６（ｄ，Ｊ＝８．８Ｈｚ，２Ｈ，ｂの芳香族プロトン）、８．２５（ｄ，Ｊ＝８．８Ｈｚ，２Ｈ，ｄの芳香族プロトン）。
【００２０】
参考例３
参考例１における４‐シアノフェノールの代りに、４‐ニトロフェノール１．３９ｇ（１０．０ミリモル）を用い、反応混合物を注加する水溶液を５重量％ＮａＨＣＯ₃水溶液に代えること以外は、参考例１と同様に操作して、式
【化１２】

で示される黄色固体状のＡｒＥＳ２−Ｎ／ＮＯ₂０．４２ｇ（収率１４．７％）を得た。このものの¹Ｈ−ＮＭＲ（ＣＤＣｌ₃）による構造解析の結果を次に示す。
δ＝３．１０［ｓ，６Ｈ，（ＣＨ₃）₂Ｎ−］、６．７４（ｄ，Ｊ＝８．８Ｈｚ，２Ｈ，ａの芳香族プロトン）、７．４０（ｄ，Ｊ＝８．８Ｈｚ，２Ｈ，ｃの芳香族プロトン）、８．０４（ｄ，Ｊ＝８．８Ｈｚ，２Ｈ，ｂの芳香族プロトン）、８．３０（ｄ，Ｊ＝８．８Ｈｚ，２Ｈ，ｄの芳香族プロトン）。
【００２１】
参考例４
４‐シアノフェノール５．００ｇ（４２．０ミリモル）に、アセトン２０ｍｌとトリエチルアミン５．８ｍｌ（４２．０ミリモル）と４‐メチルチオベンゾイルクロリド７．８４ｇ（４２．０ミリモル）をアセトン２０ｍｌに溶解した溶液とを加え、氷冷下、かきまぜながら、１夜反応させた。反応終了後、反応混合物からメチレンクロリドにより生成物を抽出し、水で６回洗浄したのち、溶媒を留去し、残留物をアセトン／水を用いて２回再結晶した。得られた残留物を室温で１夜減圧乾燥することにより、式
【化１３】

で示されるＡｒＥＳ２−Ｓ／ＣＮ８．２３ｇ（収率７２．８％）が白色固体として得られた。このものの¹Ｈ−ＮＭＲ（ＣＤＣｌ₃）による構造解析の結果を次に示す。
δ＝２．５５（ｓ，３Ｈ，ａのプロトン）、７．３２（ｄ，Ｊ＝８．４Ｈｚ，２Ｈ，ｂの芳香族プロトン）、７．３６（ｄ，Ｊ＝８．４Ｈｚ，２Ｈ，ｄの芳香族プロトン）、７．７４（ｄ，Ｊ＝８．８Ｈｚ，２Ｈ，ｅの芳香族プロトン）、８．０７（ｄ，Ｊ＝８．４Ｈｚ，２Ｈ，ｃの芳香族プロトン）。
【００２２】
参考例５
４‐ヒドロキシ安息香酸４‐シアノフェニルエステル１．００ｇ（４．１８ミリモル）に、アセトン２０ｍｌ、トリエチルアミン０．６ｍｌ（４．３３ミリモル）及びアセトン１０ｍｌに溶かした４‐メチルチオベンゾイルクロリド０．７８ｇ（４．１８ミリモル）を加え、氷冷下で１夜かきまぜることによって反応させた。反応終了後、反応混合物を塩化メチレンで抽出し、抽出液を水で４回洗浄したのち、溶媒を留去した。得られた残留物をアセトン／水を用いて２回再結晶したのち、室温下で１夜減圧乾燥することにより、式
【化１４】

で示されるＡｒＥＳ３−Ｓ／ＣＮ１．４８ｇ（収率９０．９％）を白色固体として得た。このものの¹Ｈ−ＮＭＲ（ＣＤＣｌ₃）による構造解析の結果を次に示す。
δ＝２．５９（ｓ，３Ｈ，ａのプロトン）、７．３３（ｄ，Ｊ＝８．０Ｈｚ，２Ｈ，ｂの芳香族プロトン）、７．３９（ｍ，４Ｈ，ｄ及びｆの芳香族プロトン）、７．７６（ｄ，Ｊ＝８．４Ｈｚ，２Ｈ，ｇの芳香族プロトン）、８．１０（ｄ，Ｊ＝８．０Ｈｚ，２Ｈ，ｃの芳香族プロトン）、８．２７（ｄ，Ｊ＝９．２Ｈｚ，２Ｈ，ｅの芳香族プロトン）。
【００２３】
実施例１
参考例１〜５で得たＡｒＥＳ２−Ｎ／ＣＮ、ＡｒＥＳ３−Ｎ／ＣＮ、ＡｒＥＳ２−Ｎ／ＮＯ₂、ＡｒＥＳ２−Ｓ／ＣＮ及びＡｒＥＳ３−Ｓ／ＣＮについてそれぞれをアセトニトリルに溶かして濃度１０^-5ｍｏｌ／ｌの溶液を調製した。これらの溶液について、紫外吸収スペクトルを測定し、吸収極大波長［λ_max］及びカットオフ波長［λ_CO］を求めた。その結果を表１に示す。
【００２４】
【表１】

【００２５】
実施例２
参考例１〜５で得たＡｒＥＳ２−Ｎ／ＣＮ、ＡｒＥＳ３−Ｎ／ＣＮ、ＡｒＥＳ２−Ｎ／ＮＯ₂、ＡｒＥＳ２−Ｓ／ＣＮ及びＡｒＥＳ３−Ｓ／ＣＮについてそれぞれ０．０２ｇを、ポリメチルメタクリレート０．１８ｇとクロロホルム５ｍｌに混合して２種の高分子溶液を調製した。この高分子溶液を用い、厚さ１．０ｍｍのガラス基板上に、スピンコート法（５００ｒｐｍ、３０秒間）により、厚さ約５０００Åの薄膜を形成させた。この薄膜の紫外吸収スペクトルを測定し、参考例１の溶液の紫外吸収スペクトルと比較したところ、各化合物について良好な一致が認められた。これより、各化合物は薄膜中で、分子状に分散していることが分る。次に、これらの薄膜に、種々のポーリング温度でコロナポーリング処理（５ｋＶ／ｃｍ）を施し、ポーリングの最適温度を求めた。この最適温度でポーリング処理を施したのち、メーカフリンジ法により第二高調波発生（ＳＨＧ）を測定し、常法に従って二次非線形光学係数ｄ₃₃値を算出した。その結果を表２に示す。
【００２６】
【表２】

【００２７】
【発明の効果】
本発明によれば、優れた二次非線形光学特性及び光学的透明性を有する二次非線形光学材料が提供される。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a novel organic second-order nonlinear optical material exhibiting second-order nonlinear optical characteristics.
[0002]
[Prior art]
In the future advanced information society, it will be necessary to transmit large volumes of precise information at high speed, high density, and high efficiency. And since light has characteristics such as parallel progression, spatial processing, large amount of operability, and high density, it is predicted to play an important role in this field complementing electronic technology. Recently, organic nonlinear optical materials have attracted attention as one of the materials necessary for utilizing the above.
[0003]
In contrast to the known nonlinear effects caused by the absorption of lattice vibration, the nonlinear effects caused by organic materials are dipoles that are generated by delocalized π-electron systems being distorted by substituents. Because it is due to moment and basically does not involve lattice vibration, a higher speed response is possible.
[0004]
Incidentally, second-order nonlinear optical materials are required to have optical transparency and large nonlinear optical characteristics. As such a second-order nonlinear optical material, a chained chromophore type organic nonlinear optical material has attracted attention in recent years. This chained chromophore type organic nonlinear optical material increases the μβ, which is one of the performance indexes of the second-order nonlinear optical material, in a form proportional to the square of the number of units by linearly coupling nonlinear active units. An organic material based on a concept. As one of such chained chromophore type organic nonlinear optical materials, aromatic esters and aromatic ester oligomers are known. However, although conventionally known aromatic esters and aromatic ester oligomers have good transparency, their nonlinear optical properties are not always satisfactory.
[0005]
The second-order nonlinear optical property is a phenomenon that appears only when a substance lacks a central symmetry. In the case of a polymer material, such a structure causes the nonlinear active species to be uniaxially oriented by applying an electric field. The higher the degree of orientation, the greater the performance. The magnitude of the dipole moment of the molecule is largely related to the degree of orientation, but conventional aromatic esters and aromatic ester oligomers have a dipole moment higher than that of general nonlinear active species. Since it is not so large, a good degree of orientation cannot be obtained, and as a result, it is inevitable that the second-order nonlinear optical characteristics become insufficient.
[0006]
[Problems to be solved by the invention]
The present invention has been made for the purpose of providing a second-order nonlinear optical material having good optical transparency under such circumstances.
[0007]
[Means for Solving the Problems]
As a result of intensive studies to develop aromatic oligoesters having excellent second-order nonlinear optical properties, the present inventors have introduced specific substituents composed of electron donating groups and electron withdrawing groups at the molecular ends. As a result, it was found that aromatic diesters having excellent second-order nonlinear optical properties can be obtained while maintaining a good optical transparency, and the dipole moment can be increased. The invention has been completed.
[0008]
That is, the present invention relates to the general formula (I)
[Chemical 1]

(Wherein X is a dialkylamino group having 1 to 4 carbon atoms or an alkylthio group having 1 to 4 carbon atoms, Y is a nitro group or a cyano group, and n is an integer of 1 to 3). A second-order nonlinear optical material consisting of the above is provided.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The aromatic ester of the present invention has a structure represented by the general formula (I). In the general formula (I), examples of the alkyl group in the dialkyl cyano group having 1 to 4 carbon atoms and the alkylthio group having 1 to 4 carbon atoms represented by X include, for example, methyl group, ethyl group, n-propyl group, isopropyl Group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, and the like. Among these, a methyl group is particularly preferable from the viewpoint of second-order nonlinear optical characteristics. On the other hand, Y is a nitro group or a cyano group. As n increases, the second-order nonlinear optical characteristics improve. However, when n is 5 or more, production is very complicated and impractical, so it is selected in the range of 1 to 3.
[0010]
As the aromatic oligoesters represented by the general formula (I), 4-dimethylaminobenzoic acid 4 having the following chemical structure is particularly preferable in terms of excellent optical transparency and excellent second-order nonlinear optical characteristics. -Cyanophenyl ester (hereinafter abbreviated as ArES2-N / CN), 4- (4'-dimethylaminophenylcarbonyloxy) benzoic acid 4-cyanophenyl ester (hereinafter abbreviated as ArES3-N / CN), 4-dialkyl Aminobenzoic acid 4-nitrophenyl ester (hereinafter abbreviated as ArES2-N / NO ₂ ), 4-methylthiobenzoic acid 4-cyanophenyl ester (hereinafter abbreviated as ArES2-S / CN), 4- (4′-methylthio Phenylcarbonyloxy) benzoic acid 4-cyanoester (hereinafter abbreviated as ArES3-S / CN) is preferred. .
[0011]
The esters represented by the general formula (I) are, for example, the reaction formula:

(In the formula, Hal is a halogen atom, X, Y and n have the same meaning as described above),
[Chemical 3]

(Wherein X, Hal and n have the same meaning as described above), and a general formula:

(Wherein Y has the same meaning as described above) or a p-substituted phenol in the presence of a hydrogen halide scavenger, or the reaction formula:

Wherein n ′ is an integer of 1 or 2, and X, Y and Hal have the same meaning as described above,

A p-substituted benzoic acid halide represented by the formula (wherein X and Hal have the same meaning as above);
[Chemical 7]

(Wherein Y and n ′ have the same meaning as described above) can be produced by reacting with a p-hydroxybenzoic acid derivative in the presence of a hydrogen halide scavenger.
[0012]
Examples of Hal in the compound represented by the general formula (II) or (IV) used as a raw material compound for this reaction include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom. The hydrogen halide scavenger used in this reaction is preferably a tertiary amine such as trimethylamine, triethylamine or pyridine, but other organic bases or inorganic bases can also be used.
These reactions are advantageously carried out in an inert solvent such as acetone, methyl ethyl ketone, diethyl ether, ethyl acetate, tetrahydrofuran, dimethylformamide, diethyl sulfoxide, cyclohexane.
[0013]
On the other hand, in place of the compound represented by (III) or (V) used as the starting compound of this reaction, when an alkali metal salt of the hydroxyl group, that is, phenolate is used, the desired compound can be obtained without the presence of a hydrogen halide scavenger. The reaction can be performed.
[0014]
The starting compounds (II) and (III) or (IV) and (V) in these reactions are used in substantially stoichiometric amounts, but one of the starting compounds can be used in excess if desired. . In addition, these reactions are carried out by adding the other raw material compound little by little to a solvent containing one raw material compound at room temperature or under ice cooling, and if desired, the reaction is promoted by heating. You can also As the reaction time, a range of 1 to 30 hours is usually selected. The reaction mixture thus obtained is washed with water according to a conventional method, the organic layer is separated, and the solvent is removed therefrom, whereby the target compound of the present invention is obtained as white to pale crystals.
[0015]
The p-hydroxybenzoic acid derivative represented by the general formula (V) is, for example, a p-substituted phenol of the general formula (III) and a general formula

(Wherein R is a lower alkyl group, and Hal and n 'have the same meaning as described above) and an acid anhydride represented by a solvent such as acetone in the presence of a hydrogen halide scavenger such as triethylamine The reaction is carried out under the general formula

(Wherein R is a lower alkyl group, Y and n 'have the same meaning as described above), and then hydrolyzing the compound in a solvent such as acetone in the presence of a base catalyst. Can be manufactured by.
[0016]
The compound of the present invention represented by formula (I) thus obtained is a novel compound having excellent optical transparency and excellent second-order nonlinear optical properties.
The second-order nonlinear optical properties of the polymethyl methacrylate thin film (aromatic ester content 10% by weight) having a thickness of about 5000 mm in which the aromatic esters are dispersed exist in the range where the optimal poling temperature is 60 to 90 ° C. In addition, the second-order nonlinear optical coefficient d ₃₃ value after polling at that temperature is 3 × 10 ⁻⁹ to 4 × 10 ⁻⁹ esu.
[0017]
【Example】
Next, the present invention will be described in more detail with reference to examples.
[0018]
Reference example 1
18 ml (254 mmol) of thionyl chloride was gradually added dropwise to 1.65 g (10.0 mmol) of 4-dimethylaminobenzoic acid, and the mixture was reacted by stirring for 1 hour. After completion of the reaction, excess thionyl chloride was distilled off, and 20 ml of acetone was added to the residue and dissolved to prepare an acetone solution of 4-dimethylaminobenzoyl chloride. Separately, 1.19 g (10.0 mmol) of 4-cyanophenol, 14.0 ml (101 mmol) of triethylamine and 30 ml of acetone were mixed with ice-cooled acetone solution of 4-dimethylaminobenzoyl chloride. Drip down. After completion of the dropwise addition, the reaction was stirred overnight in an ice bath, and then the reaction mixture was poured into a 5 wt% K ₂ CO ₃ aqueous solution, and the resulting precipitate was collected by filtration. Subsequently, the obtained solid was recrystallized twice with an acetone / water mixed solvent, and then dried under reduced pressure at room temperature overnight to obtain a compound represented by the formula:

As a white solid having a melting point of 152.0 to 153.5 ° C, 1.17 g of ArES2-N / CN (yield: 43.9%) was obtained. The result of structural analysis by ¹ H-NMR (CDCl ₃ ) performed at 400 MHz is shown below.
δ = 3.10 [s, 6H, (CH ₃ ) ₂ N−], 6.74 (d, J = 8.8 Hz, 2H, a aromatic proton), 7.35 (d, J = 8. 8Hz, 2H, c aromatic protons), 7.72 (d, J = 8.8 Hz, 2H, d aromatic protons), 8.04 (d, J = 8.8 Hz, 2H, b aromatics) proton).
[0019]
Reference example 2
After 9.0 ml (127 mmol) of thionyl chloride was gradually added dropwise to 0.83 g (5.00 mmol) of 4-dimethylaminobenzoic acid, the mixture was reacted by stirring for 1 hour. After completion of the reaction, excess thionyl chloride was distilled off, and 40 ml of acetone and 3.0 ml of triethylamine were added to the residue to prepare an acetone solution. Separately, a mixed solution of 1.20 g (5.00 mmol) of 4-hydroxybenzoic acid 4-cyanophenyl ester, 4.0 ml (total amount: 50.0 mmol) of triethylamine and 20 ml of acetone was prepared, and the above solution was added under ice cooling. It was dripped in the acetone solution. After completion of the dropwise addition, the reaction was stirred overnight in an ice bath, and then the reaction mixture was poured into a 5 wt% aqueous NaHCO ₃ solution. The precipitate was filtered off, recrystallized twice with an acetone / water mixed solvent, and then dried under reduced pressure at room temperature overnight. In this way, the formula

As a white solid having a melting point of 190 ° C. or higher, 0.81 g (yield 41.9%) of ArES3-N / CN was obtained. The results of structural analysis of this product by ¹ H-NMR (CDCl ₃ ) are shown below.
δ = 3.10 [s, 6H, (CH ₃ ) ₂ N−], 6.71 (d, J = 8.8 Hz, 2H, a aromatic proton), 7.38 (m, 4H, c and e aromatic protons), 7.76 (d, J = 8.8 Hz, 2H, f aromatic protons), 8.06 (d, J = 8.8 Hz, 2H, b aromatic protons), 8 .25 (d, J = 8.8 Hz, 2H, d aromatic proton).
[0020]
Reference example 3
Reference Example, except that 1.39 g (10.0 mmol) of 4-nitrophenol was used instead of 4-cyanophenol in Reference Example 1, and the aqueous solution to which the reaction mixture was poured was replaced with a 5 wt% aqueous NaHCO ₃ solution. Operate in the same way as 1 and the formula

As a result, 0.42 g (yield 14.7%) of ArES2-N / NO ₂ as a yellow solid was obtained. The results of structural analysis of this product by ¹ H-NMR (CDCl ₃ ) are shown below.
δ = 3.10 [s, 6H, (CH ₃ ) ₂ N−], 6.74 (d, J = 8.8 Hz, 2H, a aromatic proton), 7.40 (d, J = 8. 8Hz, 2H, c aromatic proton), 8.04 (d, J = 8.8 Hz, 2H, b aromatic proton), 8.30 (d, J = 8.8 Hz, 2H, d aromatic proton) proton).
[0021]
Reference example 4
A solution of 20 ml of acetone, 5.8 ml (42.0 mmol) of triethylamine and 7.84 g (42.0 mmol) of 4-methylthiobenzoyl chloride in 20 ml of acetone in 5.00 g (42.0 mmol) of 4-cyanophenol The mixture was allowed to react overnight with stirring under ice cooling. After completion of the reaction, the product was extracted from the reaction mixture with methylene chloride, washed 6 times with water, the solvent was distilled off, and the residue was recrystallized twice with acetone / water. The resulting residue was dried in vacuo overnight at room temperature to yield the formula

In this manner, 8.23 g (yield 72.8%) of ArES2-S / CN represented by the following formula was obtained as a white solid. The results of structural analysis of this product by ¹ H-NMR (CDCl ₃ ) are shown below.
δ = 2.55 (protons of s, 3H, a), 7.32 (aromatic protons of d, J = 8.4 Hz, 2H, b), 7.36 (d, J = 8.4 Hz, 2H, d aromatic aromatic proton), 7.74 (d, J = 8.8 Hz, 2H aromatic aromatic proton), 8.07 (d, J = 8.4 Hz, 2H aromatic aromatic proton).
[0022]
Reference Example 5
To 1.00 g (4.18 mmol) of 4-hydroxybenzoic acid 4-cyanophenyl ester, 0.78 g of 4-methylthiobenzoyl chloride dissolved in 20 ml of acetone, 0.6 ml (4.33 mmol) of triethylamine and 10 ml of acetone (4 .18 mmol) was added and the reaction was allowed to stir overnight under ice cooling. After completion of the reaction, the reaction mixture was extracted with methylene chloride, and the extract was washed 4 times with water, and then the solvent was distilled off. The obtained residue was recrystallized twice using acetone / water, and then dried under reduced pressure at room temperature overnight to obtain a compound represented by the formula:

As a white solid, 1.48 g (90.9% yield) of ArES3-S / CN was obtained. The results of structural analysis of this product by ¹ H-NMR (CDCl ₃ ) are shown below.
δ = 2.59 (protons of s, 3H, a), 7.33 (aromatic protons of d, J = 8.0 Hz, 2H, b), 7.39 (aromatics of m, 4H, d and f) Proton), 7.76 (aromatic proton of d, J = 8.4 Hz, 2H, g), 8.10 (aromatic proton of d, J = 8.0 Hz, 2H, c), 8.27 (d , J = 9.2 Hz, 2H, e aromatic protons).
[0023]
Example 1
ArES2-N / CN, ArES3-N / CN, ArES2-N / NO ₂ , ArES2-S / CN and ArES3-S / CN obtained in Reference Examples 1 to 5 were each dissolved in acetonitrile to have a concentration of 10 ⁻⁵ mol. / L solution was prepared. About these solutions, the ultraviolet absorption spectrum was measured, and the absorption maximum wavelength [λ _max ] and the cutoff wavelength [λ _CO ] were determined. The results are shown in Table 1.
[0024]
[Table 1]

[0025]
Example 2
For ArES2-N / CN, ArES3-N / CN, ArES2-N / NO ₂ , ArES2-S / CN and ArES3-S / CN obtained in Reference Examples 1 to 5, 0.02 g of polymethyl methacrylate Two polymer solutions were prepared by mixing 18 g and 5 ml of chloroform. Using this polymer solution, a thin film having a thickness of about 5000 mm was formed on a glass substrate having a thickness of 1.0 mm by spin coating (500 rpm, 30 seconds). When the ultraviolet absorption spectrum of this thin film was measured and compared with the ultraviolet absorption spectrum of the solution of Reference Example 1, good agreement was found for each compound. From this, it can be seen that each compound is dispersed in a molecular form in the thin film. Next, these thin films were subjected to corona poling treatment (5 kV / cm) at various poling temperatures to obtain the optimum poling temperature. After poling at this optimum temperature, second harmonic generation (SHG) was measured by the manufacturer fringe method, and the second-order nonlinear optical coefficient d ₃₃ value was calculated according to a conventional method. The results are shown in Table 2.
[0026]
[Table 2]

[0027]
【The invention's effect】
According to the present invention, a second-order nonlinear optical material having excellent second-order nonlinear optical properties and optical transparency is provided.

Claims (1)

Formula (I)

(Wherein X is a dialkylamino group having 1 to 4 carbon atoms or an alkylthio group having 1 to 4 carbon atoms, Y is a nitro group or a cyano group, and n is an integer of 1 to 3). A second-order nonlinear optical material consisting of