JP3593710B2 - Dichroic dye, liquid crystal composition containing the dye, and liquid crystal device - Google Patents

Description

【０００８】
（式中、Ｒ¹、Ｒ²はそれぞれアルキル基、アルコキシアルキル基、フルオロアルキル置換アルキル基、または置換基を有していてもよいアラルキル基を示す。なおＲ¹、Ｒ²は互に連結して含窒素脂肪族環を形成してもよく、更にはＲ ¹ とＺ ⁹ 及び／又はＲ ² とＺ ⁸ も互に連結してテトラヒドロキノリン環またはジュロリジン環を形成してもよい。Ｒfは炭素数１〜１２のパーフルオロアルキル基または、ω−Ｈ−パーフルオロアルキル基を示し、ｍは１または２、ｎは１〜８の数を示し、Ｚ¹〜Ｚ⁹は水素原子、ハロゲン原子、メチル基またはメトキシ基を示し、Ｚ¹とＺ²、Ｚ⁴とＺ⁵またはＺ⁷とＺ⁸は互に連結して脂肪族環、芳香族環または含窒素芳香環を形成してもよい。）で表されるパーフルオロアルキルアルキルメルカプト基を含有するジスアゾ系又はトリスアゾ系二色性色素に存する。本発明のジス又はトリスアゾ系二色性色素は下記の反応式［II］または［III］
【０００９】
【化３】

【００１０】
により、合成されるパーフルオロアルキルアルキルメルカプト基を含むアニリン類を用いて、公知のジアゾ化カップリング反応を適用することにより合成することができる。
【００１１】
前示一般式〔Ｉ〕に於けるＲ^１ 、Ｒ^２ はそれぞれ独立にメチル、エチル、直鎖状または分枝状のプロピル、ブチル、ヘキシル、オクチルなどの炭素数１〜１８のアルキル基、エトキシメチル、ブトキシメチル、エトキシエチル、ブトキシエチルなどのアルコキシアルキル基、パーフルオロエチルメチル、パーフルオロブチルエチル、パーフルオロヘキシルエチルなどのフルオロアルキル置換アルキル基、ベンジル、フェネチル、４−ブチルベンジル、４−ブトキシエチルベンジル、４−ペントキシベンジル、４−クロルベンジルなどのアルキル基、アルコキシアルキル基、アルコキシ基、ハロゲン原子などの置換基を有していてもよいアラルキル基が挙げられ、またＲ^１ 、Ｒ^２ は互に結合してピロリジン環、ピペリジン環、モルホリン環などの含窒素脂肪族環を形成してもよい。
【００１２】
Ｒｆはパーフルオロメチル、パーフルオロブチル、パーフルオロヘキシルなどの炭素数１〜１２のパーフルオロアルキル基もしくは、４−Ｈ−パーフルオロブチル、６−Ｈ−パーフルオロヘキシルなどの炭素数１〜１２のω−Ｈ−パーフルオロアルキル基を示す。
ｍは１または２、ｎは１〜８の数を表す。
【００１３】
Ｚ^１ 〜Ｚ^９ はそれぞれ水素原子、塩素原子、フッ素原子、臭素原子、などのハロゲン原子、メチル基、エチル基を示し、Ｚ^１ とＺ^２ 、Ｚ^４ とＺ^５ またはＺ^７ とＺ^８ は互に連結してテトラリン環の脂肪族環部分、ナフタリン環の芳香族環部分またはキノリン環の含窒素芳香環部分を形成してもよく、Ｒ^１ とＺ^８ またはＲ^２ とＺ^９ は互に連結してジュロリジン環、テトラヒドロキノリン環の含窒素脂肪族環部分を形成してもよい。
本発明の二色性色素の中でも、特にジスアゾ系色素は特に赤色系でも青味赤色〜赤紫の深色系の色相を有する為、ブラックの液晶組成物の成分として有用である。
【００１４】
本発明の液晶組成物は前示一般式〔Ｉ〕で示されるアゾ系二色性色素を、〔液晶デバイスハンドブック；日本学術振興会第１４２委員会編（１９８９）；ｐ１５４〜ｐ１９２，ｐ７１５〜ｐ７２２〕記載のネマチックあるいはスメクチック相を示すビフェニル系、フェニルシクロヘキサン系、フェニルピリミジン系、シクロヘキシルシクロヘキサン系などの各種の液晶化合物または液晶組成物に公知の方法で混合することにより容易に調製することができる。このような液晶化合物の例としては、特開平３−１４８９２号公報等に記載の化合物が挙げられる。この他、ＴＦＴ液晶素子に用いられるフッ素系液晶も好適に使用できる。
【００１５】
また本発明の液晶組成物はコレステリルノナノエートなどの、液晶相を示しても示さなくても良い光学活性化合物、あるいは紫外線吸収剤、酸化防止剤などの各種の添加剤を含有しても良い。
【００１６】
このようにして得られた液晶組成物を、少なくとも一方が透明な電極付基板間に挟持することにより、ゲストホスト効果を応用した素子〔松本正一、角田市良“液晶の最新技術”工業調査会，３４（１９８３）；Ｊ．Ｌ．Ｆｅｒｇａｓｏｎ，ＳＩＤ８５Ｄｉｇｅｓｔ，６８（１９８５）等〕などを構成することができる。該基板としては通常ガラス板或いはアクリル樹脂、ポリカーボネート樹脂、エポキシ樹脂等の各種合成樹脂板が挙げられ、その基板上に電極層が形成される。透明電極層としては、酸化インジウム、酸化インジウムスズ（ＩＴＯ）、酸化スズ等の金属酸化物から成るものが通常使用される。透明電極層の液晶に接する表面は必要に応じて配向処理を施す。該配向処理の方法としては、例えばポリイミドを塗布して平行配向にする方法、ＳｉＯを斜めの角度から蒸着して平行配向にする方法等が適宜用いられる。
【００１７】
通常、基体は互に配向処理層面が対向するようにしてスペーサー等を介して一体化し、１〜５０μｍ好ましくは１〜１５μｍの素子間隔の素子を構成し、この素子間隔の中に液晶を封入することにより液晶素子を作成する。
【００１８】
【発明の効果】
本発明の高い二色性と高い着色力をもつ赤色系の二色性色素およびこれを含むフッ素系液晶組成物などにより、コントラストおよび耐久性に優れた表示素子などの液晶素子を構成することができる。
【００１９】
【実施例】
次に、本発明を実施例により、具体的に説明するが本発明はこれら実施例により何ら限定されるものではない。
【００２０】
実施例１
ジメチルホルムアミド２０ｍｌにｐ−アミノチオフェノール２４ｍｍｏｌを加えて、攪拌下にナトリウムハイドライド３０ｍｍｏｌを添加し、室温で３時間攪拌したのち、２−（パーフルオロブチル）エチルアイオダイド３０ｍｍｏｌを加えて、窒素雰囲気下に室温で一夜間攪拌して反応させた。次いで反応混合物を水１５０ｍｌ中に排出してエーテルを用いて抽出した。エーテル層を洗浄、乾燥後、溶媒を留去したのち、蒸留精製して下記構造の化合物を得た。
【００２１】
【化４】

【００２２】
以下に本化合物の物性値を示す。
ｂｐ １１４℃／１３０ｐａ；
^１Ｈ ＮＭＲ（ＣＤＣｌ_３ ）δ２．３１（ｔｔ，Ｊ＝１６．８ａｎｄ８．２Ｈｚ，２Ｈ），２．９３（ｔｔ，Ｊ＝８．２ａｎｄ３．２Ｈｚ，２Ｈ），３．７５（ｂｒ ｓ，２Ｈ），６．６５（ｄ，Ｊ＝８．５Ｈｚ，２Ｈ），７．２６（ｄ，Ｊ＝８．５Ｈｚ，２Ｈ）；
ＥＩＭＳ（７０ｅＶ）ｍ／ｚ（ｒｅｌ ｉｎｔｅｎｓｉｔｙ）３７１（Ｍ^＋ ，１００），１２４（８８）．
【００２３】
この化合物０．３ｇ（０．８ｍｍｏｌ）を含む酢酸溶液１０ｍｌに４−ニトロソニトロベンゼン０．１２ｇ（０．８ｍｍｏｌ）を加え常法により反応させ、室温で一夜攪拌し、反応物を濾取し水洗後乾燥し、下記の化合物を得た。
【００２４】
【化５】

【００２５】
この化合物の物性値を以下に示す。
ｍｐ １１９−１２０℃；
^１Ｈ ＮＭＲ（ＣＤＣｌ_３ ）δ２．４９（ｔｔ，Ｊ＝１６．５ａｎｄ８．２Ｈｚ，２Ｈ），３．２６（ｔｔ，Ｊ＝８．２ａｎｄ３．２Ｈｚ，２Ｈ），７．４５（ｄ，Ｊ＝８．８Ｈｚ，２Ｈ），７．９６（ｄ，Ｊ＝８．８Ｈｚ，２Ｈ），８．０３（ｄ，Ｊ＝９．１Ｈｚ，２Ｈ），８．３９（ｄ，Ｊ＝９．１Ｈｚ，２Ｈ）；
ＥＩＭＳ（７０ｅＶ）ｍ／ｚ（ｒｅｌ ｉｎｔｅｎｓｉｔｙ）５０５（Ｍ^＋ ，５２），３５５（１００），１２２（２２）．
【００２６】
この化合物０．２５ｇ（０．５ｍｍｏｌ）を含む８５％エタノール溶液１００ｍｌにＮａ_２ Ｓ（１ｍｍｏｌ）の水溶液５ｍｌを加え、１時間還流し、反応させた。反応混合物を水３０ｍｌへ排出し、析出物を濾取し、水洗し乾燥後にジクロロメタンを用いてカラムクロマトにより精製し、下記構造のモノアゾ化合物を得た。
【００２７】
【化６】

【００２８】
このモノアゾ化合物の物性値を以下に示す。
ｍｐ ９７−９８℃；
^１Ｈ ＮＭＲ（ＣＤＣｌ_３ ）δ２．４４（ｔｔ，Ｊ＝１６．６ａｎｄ８．１Ｈｚ，２Ｈ），３．１９（ｔｔ，Ｊ＝８．１ａｎｄ２．９Ｈｚ，２Ｈ），４．０６（ｂｒ ｓ，２Ｈ），６．７４（ｄ，Ｊ＝８．９Ｈｚ，２Ｈ），７．４３（ｄ，Ｊ＝８．７Ｈｚ，２Ｈ），７．８０（ｄ，Ｊ＝８．９Ｈｚ，２Ｈ），７．８２（ｄ，Ｊ＝８．７Ｈｚ，２Ｈ）；
ＥＩＭＳ（７０ｅＶ）ｍ／ｚ（ｒｅｌ ｉｎｔｅｎｓｉｔｙ）４７５（Ｍ^＋ ，６０），１２０（４０），９２（１００）．
【００２９】
上記構造式で示されるパーフルオロアルキルアルキルメルカプト基を含有するモノアゾ系化合物０．５ｇをアセトン、ジメチルホルムアミド（ＤＭＦ）、水混合物（アセトン：ＤＭＦ：水＝２：０．５：０．５）２５ｍｌ、濃塩酸０．２５ｍｌに溶解させ、０℃に冷却して亜硝酸ナトリウム０．０７ｇを含む水溶液５ｍｌを加え、１５分後、このジアゾ液にＮ，Ｎ−ジエチルアニリン０．３ｇを含むアセトン５ｍｌを０℃で攪拌下に加え、同温度で１時間反応させた後、反応物を過剰の水に排出して析出物を濾取し、ジクロルメタンを用いてカラムクロマトにより精製して下記構造式の色素を得た。
【００３０】
【化７】

【００３１】
この色素の物性値を以下に示す。
λｍａｘ（ヘキサン）：４６６ｎｍ
ｍｐ １３８−１４０℃；
^１Ｈ ＮＭＲ（ＣＤＣｌ_３ ）δ１．２５（ｔ，Ｊ＝７．０，Ｈｚ，６Ｈ），２．４７（ｔｔ，Ｊ＝１８．６ａｎｄ８．２Ｈｚ，２Ｈ），３．２３（ｔｔ，Ｊ＝８．２ａｎｄ２．９Ｈｚ，２Ｈ），３．４８（ｑ，Ｊ＝７．０Ｈｚ，４Ｈ），６．７５（ｄ，Ｊ＝９．２Ｈｚ，２Ｈ），７．４５（ｄ，Ｊ＝８．４Ｈｚ，２Ｈ），７．９０（ｄ，Ｊ＝９．２Ｈｚ，２Ｈ），７．９２（ｄ，Ｊ＝８．４Ｈｚ，２Ｈ）７．９７（ｄ，Ｊ＝８．８Ｈｚ，２Ｈ），８．０３（ｄ，Ｊ＝８．８Ｈｚ，２Ｈ）；
ＥＩＭＳ（７０ｅＶ）ｍ／ｚ（ｒｅｌ ｉｎｔｅｎｓｉｔｙ）６３５（Ｍ^＋ ，４０），６２０（１８），１７６（１２），１４８（１００）．
【００３２】
このアゾ系色素を商品名ＺＬ１−１５６５（Ｅ．ＭＥＲＣＫ社製）として市販されているフェニルシクロヘサキン系液晶混合物に１ｗｔ％の濃度で溶解させ赤色のゲストホスト型液晶組成物を調製した。これをポリイミド系樹脂を塗布、硬化、ラビング処理した透明電極付きガラス基板を対向させ、液晶が平行配向となるように構成したギャップ９μｍのセルに封入した。
【００３３】
この赤色に着色したセルの配向方向に平行な直線偏光に対する吸光度（Ａ／／）および配向方向に垂直な直線偏光に対する吸光度（Ａ⊥）を測定し、その吸収ピーク（λｍａｘ：５０２ｎｍ）におけるオーダーパラメータ（Ｓ）を下記の式
Ｓ＝（Ａ／／−Ａ⊥）／（Ａ／／＋２Ａ⊥）
から求めた結果、Ｓ＝０．７７であった。
上記のＺＬＩ−１５６５の代りに商品名ＺＬＩ−４７９２（Ｅ．ＭＥＲＣＫ社製）として市販されているフッ素系液晶混合物を用いて、同様にしてオーダーパラメータを求めた結果、Ｓ＝０．７７（λｍａｘ：４９８ｎｍ）であった。
【００３４】
実施例２
下記構造式で示されるパーフルオロアルキルアルキルメルトカプト基を含有するモノアゾ系化合物
【００３５】
【化８】

【００３６】
を用いて、実施例１と同様にして下記構造式の色素を得た。
【００３７】
【化９】

【００３８】
この色素の物性値を以下に示す。
λｍａｘ（ヘキサン）：４６８ｎｍ
ｍｐ １１８−１１９℃；
^１Ｈ ＮＭＲ（ＣＤＣｌ_３ ）δ１．２５（ｔ，Ｊ＝７．３，Ｈｚ，６Ｈ），２．４７（ｔｔ，Ｊ＝１７．１ａｎｄ８．２Ｈｚ，２Ｈ），３．２３（ｔｔ Ｊ＝８．２ａｎｄ３．１Ｈｚ，２Ｈ），３．４８（ｑ，Ｊ＝７．３Ｈｚ，４Ｈ），６．７４（ｄ，Ｊ＝９．２Ｈｚ，２Ｈ），７．４５（ｄ，Ｊ＝９．２Ｈｚ，２Ｈ），７．９０（ｄ，Ｊ＝９．２Ｈｚ，２Ｈ），７．９２（ｄ，Ｊ＝８．５Ｈｚ，２Ｈ）７．９６（ｄ，Ｊ＝９．２Ｈｚ，２Ｈ），８．０３（ｄ，Ｊ＝８．５Ｈｚ，２Ｈ）；
ＥＩＭＳ（７０ｅＶ）ｍ／ｚ（ｒｅｌ ｉｎｔｅｎｓｉｔｙ）７３５（Ｍ^＋ ，９５），７２０（３８），１４８（１００）．
【００３９】
このアゾ系色素を実施例１と同様にして商品名ＺＬＩ−４７９２（Ｅ．ＭＥＲＣＫ社製）として市販されているフッ素系液晶混合物を用いて、オーダーパラメーター（Ｓ）を求めた結果、Ｓ＝０．７４（λｍａｘ：４９８ｎｍ）であった。
【００４０】
実施例３
上記の実施例１，２に準じた方法により得られたアゾ系色素のフッ素系液晶混合物：商品名ＺＬＩ−４７９２（Ｅ．ＭＥＲＣＫ社製）中におけるオーダーパラメーター（Ｓ）と色相を表−１に示す。
【００４１】
【表１】

【００４２】
【表２】

[0001]
[Industrial applications]
The present invention relates to a novel red to blue azo dichroic dye, a liquid crystal composition containing the same, and a liquid crystal device.
[0002]
[Prior art]
At present, various display modes other than a twist nematic (TN) type display mode and a super twist (STN) mode have been proposed as liquid crystal displays. Among them, a guest-host (GH) type display system using a dye dissolved in a liquid crystal is widely used as a display panel of an automobile or the like because of a feature such as a wide viewing angle.
[0003]
As the characteristics of the dichroic dye used in the GH mode, the following items 1) dichroism 2) solubility 3) light resistance 4) excellent coloring power are required.
[0004]
On the other hand, as the red dichroic dye required for forming a black liquid crystal composition having a large market need, a dye having an alkyl group, a nitro group, or a cyano group at a terminal has been conventionally known. . As a substituent containing a fluorine atom, a trifluoromethyl group has been studied, but other groups are not yet sufficient.
However, conventional dichroic dyes having a nitro group or a cyano group have great disadvantages in light resistance and solubility, and dyes having an alkyl group tend to have a pale hue such as yellowish red and bluish red. However, it is difficult to obtain a deep color hue.
Further, there is a problem that these conventional dyes have insufficient affinity such as solubility with respect to a fluorine-based liquid crystal compound used in recent TFT liquid crystal devices and the like.
[0005]
[Problems to be solved by the invention]
An object of the present invention is to provide a red dichroic dye having less of the above-mentioned difficulties, a liquid crystal composition containing the same, and a liquid crystal element.
[0006]
[Means for Solving the Problems]
The present inventors have found that a disazo-based or trisazo-based red dye having a perfluoroalkylalkylmercapto group exhibits excellent dichroism and coloring properties, and reached the present invention. That is, the gist of the present invention is represented by the following general formula [I]
[0007]
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[0008]
(Wherein, R ^1, R ² are each an alkyl group, an alkoxyalkyl group, shows the fluoroalkyl-substituted alkyl group or an aralkyl group which may have a substituent. In addition R ^1, R ² are mutually coupled to rather it may also form a nitrogen-containing aliphatic ring, and further may form a tetrahydroquinoline ring or julolidine ring by linking each other also R ¹ and Z ⁹ and / or R ² and Z ^8. Rf is also a perfluoroalkyl group having 1 to 12 carbon atoms, omega-H- perfluoroalkyl group indicates, m is 1 or 2, n is a number of 1 to 8, Z ¹ to Z ⁹ is hydrogen, A halogen atom, a methyl group or a methoxy group, Z ¹ and Z ² , Z ⁴ and Z ⁵ or Z ⁷ and Z ⁸ are linked to each other to form an aliphatic ring, an aromatic ring or a nitrogen-containing aromatic ring; Perfluoroalkylalkyl mercapto group represented by Disazo or trisazo dichroic dyes. The di- or trisazo-based dichroic dye of the present invention has the following reaction formula [II] or [III]
[0009]
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[0010]
Can be synthesized by applying a known diazotization coupling reaction using an aniline containing a perfluoroalkylalkylmercapto group to be synthesized.
[0011]
In the general formula [I], R ¹ and R ² each independently represent an alkyl group having 1 to 18 carbon atoms such as methyl, ethyl, linear or branched propyl, butyl, hexyl, octyl, etc .; Alkoxyalkyl groups such as methyl, butoxymethyl, ethoxyethyl and butoxyethyl, fluoroalkyl-substituted alkyl groups such as perfluoroethylmethyl, perfluorobutylethyl and perfluorohexylethyl, benzyl, phenethyl, 4-butylbenzyl, 4-butoxy ethylbenzyl, 4-pentoxy-benzyl, 4-chlorophenyl alkyl group such as benzyl, alkoxyalkyl group, alkoxy group, and aralkyl group which may have a substituent such as a halogen atom, and R ^1, R ² Are bonded to each other to form a pyrrolidine ring, piperidine ring, morpholine ring Which nitrogen-containing aliphatic ring may be formed.
[0012]
Rf is a perfluoroalkyl group having 1 to 12 carbon atoms such as perfluoromethyl, perfluorobutyl and perfluorohexyl, or a 1 to 12 carbon atom such as 4-H-perfluorobutyl and 6-H-perfluorohexyl. represents an ω-H-perfluoroalkyl group.
m represents 1 or 2, and n represents a number of 1 to 8.
[0013]
Z ^{1 to} Z ⁹ each represent a hydrogen atom, a chlorine atom, a fluorine atom, a bromine atom, or another halogen atom, a methyl group or an ethyl group, and Z ¹ and Z ² , Z ⁴ and Z ^5, or Z ⁷ and Z ⁸ represent R ¹ and Z ⁸ or R ² and Z ⁹ may be linked to each other to form an aliphatic ring portion of a tetralin ring, an aromatic ring portion of a naphthalene ring or a nitrogen-containing aromatic ring portion of a quinoline ring. They may be linked to form a nitrogen-containing aliphatic ring moiety of a julolidine ring or a tetrahydroquinoline ring.
Among the dichroic dyes of the present invention, disazo dyes are particularly useful as a component of a black liquid crystal composition because they have a deep red to reddish purple hue even in a red color.
[0014]
The liquid crystal composition of the present invention comprises an azo dichroic dye represented by the general formula [I] described above [Liquid crystal device handbook; edited by the 142nd Committee of the Japan Society for the Promotion of Science (1989); p154-p192, p715-p722. The compound can be easily prepared by mixing a liquid crystal compound or a liquid crystal composition such as a biphenyl-based, phenylcyclohexane-based, phenylpyrimidine-based, or cyclohexylcyclohexane-based compound having a nematic or smectic phase described above with a known method. Examples of such a liquid crystal compound include compounds described in JP-A-3-14892 and the like. In addition, a fluorine-based liquid crystal used for a TFT liquid crystal element can be preferably used.
[0015]
The liquid crystal composition of the present invention may contain an optically active compound which may or may not show a liquid crystal phase, such as cholesteryl nonanoate, or various additives such as an ultraviolet absorber and an antioxidant.
[0016]
An element utilizing the guest-host effect by sandwiching the thus obtained liquid crystal composition between substrates with at least one transparent electrode [Shoichi Matsumoto, Ichiyo Tsunoda “Latest Technology of Liquid Crystal” Association, 34 (1983); L. Fergason, SID85Digest, 68 (1985), etc.]. Examples of the substrate include a glass plate or various synthetic resin plates such as an acrylic resin, a polycarbonate resin, and an epoxy resin. An electrode layer is formed on the substrate. As the transparent electrode layer, one composed of a metal oxide such as indium oxide, indium tin oxide (ITO), and tin oxide is usually used. The surface of the transparent electrode layer in contact with the liquid crystal is subjected to an alignment treatment as needed. As a method of the alignment treatment, for example, a method of applying polyimide to make parallel alignment, a method of depositing SiO from an oblique angle to make parallel alignment, and the like are appropriately used.
[0017]
Normally, the substrates are integrated via a spacer or the like so that the surfaces of the alignment treatment layers face each other to form an element having an element interval of 1 to 50 μm, preferably 1 to 15 μm, and a liquid crystal is sealed in the element interval. Thus, a liquid crystal element is created.
[0018]
【The invention's effect】
By using the red dichroic dye having high dichroism and high coloring power of the present invention and a fluorine-based liquid crystal composition containing the same, a liquid crystal element such as a display element having excellent contrast and durability can be formed. it can.
[0019]
【Example】
Next, the present invention will be described specifically with reference to examples, but the present invention is not limited to these examples.
[0020]
Example 1
24 mmol of p-aminothiophenol was added to 20 ml of dimethylformamide, 30 mmol of sodium hydride was added with stirring, and the mixture was stirred at room temperature for 3 hours. Then, 30 mmol of 2- (perfluorobutyl) ethyl iodide was added, and the mixture was added under a nitrogen atmosphere. The reaction was stirred overnight at room temperature. The reaction mixture was then drained into 150 ml of water and extracted with ether. After washing and drying the ether layer, the solvent was distilled off, and the residue was purified by distillation to obtain a compound having the following structure.
[0021]
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[0022]
The physical properties of the compound are shown below.
bp 114 ° C / 130pa;
¹ H NMR (CDCl ₃ ) δ 2.31 (tt, J = 16.8 and 8.2 Hz, 2H), 2.93 (tt, J = 8.2 and 3.2 Hz, 2H), 3.75 (br s, 2H) , 6.65 (d, J = 8.5 Hz, 2H), 7.26 (d, J = 8.5 Hz, 2H);
EIMS (70 eV) m / z (rel intensity) 371 (M ⁺ , 100), 124 (88).
[0023]
To 10 ml of an acetic acid solution containing 0.3 g (0.8 mmol) of this compound was added 0.12 g (0.8 mmol) of 4-nitrosonitrobenzene, and the mixture was reacted in a conventional manner. The mixture was stirred at room temperature overnight, and the reaction product was filtered and washed with water. After drying, the following compound was obtained.
[0024]
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[0025]
The physical properties of this compound are shown below.
mp 119-120 ° C;
¹ H NMR (CDCl ₃ ) δ 2.49 (tt, J = 16.5 and 8.2 Hz, 2H), 3.26 (tt, J = 8.2 and 3.2 Hz, 2H), 7.45 (d, J = 8) .8 Hz, 2H), 7.96 (d, J = 8.8 Hz, 2H), 8.03 (d, J = 9.1 Hz, 2H), 8.39 (d, J = 9.1 Hz, 2H) ;
EIMS (70 eV) m / z (rel intensity) 505 (M ⁺ , 52), 355 (100), 122 (22).
[0026]
To 100 ml of an 85% ethanol solution containing 0.25 g (0.5 mmol) of this compound was added 5 ml of an aqueous solution of Na ₂ S (1 mmol), and the mixture was refluxed for 1 hour to react. The reaction mixture was discharged into 30 ml of water, and the precipitate was collected by filtration, washed with water, dried, and then purified by column chromatography using dichloromethane to obtain a monoazo compound having the following structure.
[0027]
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[0028]
The physical properties of this monoazo compound are shown below.
mp 97-98 ° C;
¹ H NMR (CDCl ₃ ) δ 2.44 (tt, J = 16.6 and 8.1 Hz, 2H), 3.19 (tt, J = 8.1 and 2.9 Hz, 2H), 4.06 (br s, 2H) , 6.74 (d, J = 8.9 Hz, 2H), 7.43 (d, J = 8.7 Hz, 2H), 7.80 (d, J = 8.9 Hz, 2H), 7.82 ( d, J = 8.7 Hz, 2H);
EIMS (70 eV) m / z (rel intensity) 475 (M ⁺ , 60), 120 (40), 92 (100).
[0029]
0.5 g of a monoazo compound containing a perfluoroalkylalkylmercapto group represented by the above structural formula is mixed with 25 ml of acetone, dimethylformamide (DMF) and water (acetone: DMF: water = 2: 0.5: 0.5). Dissolved in 0.25 ml of concentrated hydrochloric acid, cooled to 0 ° C. and added with 5 ml of an aqueous solution containing 0.07 g of sodium nitrite. After 15 minutes, 5 ml of acetone containing 0.3 g of N, N-diethylaniline was added to the diazo solution. Was added under stirring at 0 ° C., and reacted at the same temperature for 1 hour. The reaction product was discharged into excess water, the precipitate was collected by filtration, purified by column chromatography using dichloromethane, and purified by the following structural formula. A dye was obtained.
[0030]
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[0031]
The physical properties of this dye are shown below.
λmax (hexane): 466 nm
mp 138-140 ° C;
¹ H NMR (CDCl ₃ ) δ 1.25 (t, J = 7.0, Hz, 6H), 2.47 (tt, J = 18.6 and 8.2 Hz, 2H), 3.23 (tt, J = 8) .2 and 2.9 Hz, 2H), 3.48 (q, J = 7.0 Hz, 4H), 6.75 (d, J = 9.2 Hz, 2H), 7.45 (d, J = 8.4 Hz, 2H), 7.90 (d, J = 9.2 Hz, 2H), 7.92 (d, J = 8.4 Hz, 2H) 7.97 (d, J = 8.8 Hz, 2H), 8.03 (D, J = 8.8 Hz, 2H);
EIMS (70 eV) m / z (rel intensity) 635 (M ⁺ , 40), 620 (18), 176 (12), 148 (100).
[0032]
This azo dye was dissolved at a concentration of 1 wt% in a phenylcyclohesaquine liquid crystal mixture commercially available as trade name ZL1-1565 (manufactured by E. MERCK) to prepare a red guest-host type liquid crystal composition. A glass substrate with a transparent electrode, which was coated with a polyimide resin, cured and rubbed, faced, and was sealed in a cell with a gap of 9 μm configured so that the liquid crystal was aligned in parallel.
[0033]
The absorbance (A //) for linearly polarized light parallel to the orientation direction and the absorbance (A⊥) for linearly polarized light perpendicular to the orientation direction of the cell colored in red were measured, and the order parameter at the absorption peak (λmax: 502 nm) was measured. (S) is calculated by the following equation: S = (A / −− A⊥) / (A / + 2A⊥)
As a result, S = 0.77.
As a result of similarly determining the order parameter using a fluorine-based liquid crystal mixture commercially available as trade name ZLI-4792 (manufactured by E. MERCK) instead of ZLI-1565, S = 0.77 (λmax) : 498 nm).
[0034]
Example 2
A monoazo compound having a perfluoroalkylalkylmercapto group represented by the following structural formula:
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[0036]
And a dye having the following structural formula was obtained in the same manner as in Example 1.
[0037]
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[0038]
The physical properties of this dye are shown below.
λmax (hexane): 468 nm
mp 118-119 ° C;
¹ H NMR (CDCl ₃ ) δ 1.25 (t, J = 7.3 Hz, 6H), 2.47 (tt, J = 17.1 and 8.2 Hz, 2H), 3.23 (tt J = 8.2. 2 and 3.1 Hz, 2H), 3.48 (q, J = 7.3 Hz, 4H), 6.74 (d, J = 9.2 Hz, 2H), 7.45 (d, J = 9.2 Hz, 2H) ), 7.90 (d, J = 9.2 Hz, 2H), 7.92 (d, J = 8.5 Hz, 2H) 7.96 (d, J = 9.2 Hz, 2H), 8.03 ( d, J = 8.5 Hz, 2H);
EIMS (70 eV) m / z (rel intensity) 735 (M ⁺ , 95), 720 (38), 148 (100).
[0039]
The order parameter (S) of this azo dye was determined using a fluorine-based liquid crystal mixture commercially available under the trade name ZLI-4792 (manufactured by E. MERCK) in the same manner as in Example 1, and as a result, S = 0. .74 (λmax: 498 nm).
[0040]
Example 3
Table 1 shows the order parameter (S) and hue in a fluorinated liquid crystal mixture of an azo dye obtained by a method according to the above Examples 1 and 2: trade name ZLI-4792 (manufactured by E. MERCK). Show.
[0041]
[Table 1]

[0042]
[Table 2]

Claims (3)

The following general formula [I]

(Wherein, R ^1, R ² are each an alkyl group, an alkoxyalkyl group, shows the fluoroalkyl-substituted alkyl group or an aralkyl group which may have a substituent. In addition R ^1, R ² are mutually coupled to rather it may also form a nitrogen-containing aliphatic ring, and further may form a tetrahydroquinoline ring or julolidine ring by linking each other also R ¹ and Z ⁹ and / or R ² and Z ^8. Rf Is 1 carbon
Or 12 perfluoroalkyl group, an omega-H- perfluoroalkyl group, m is 1 or 2, n is a number of 1 to 8, Z ¹ to Z ⁹ is a hydrogen atom, a halogen atom, methyl represents a group or a methoxy group, Z ¹ and Z ^2, Z ⁴ and Z ⁵ or Z ⁷ and Z ⁸ are connected one to another aliphatic ring, it may form an aromatic ring or a nitrogen-containing aromatic ring. A) a diazo or trisazo dichroic dye containing a perfluoroalkylalkylmercapto group represented by the formula: A liquid crystal composition comprising a liquid crystal compound and a disazo or trisazo dichroic dye having a perfluoroalkylalkyl mercapto group according to claim 1. A liquid crystal device comprising the liquid crystal composition according to claim 2 sandwiched between two substrates with electrodes, at least one of which is transparent.