A new homologous series of mesogens containing 6-amino-1,3-dimethyluracil moiety have been synthesized. The structures of the compounds were characterised by elemental analysis, FT-IR, 1H and 13C NMR spectroscopic techniques. Their mesomorphic properties were studied by polarising optical microscopy attached to a heating stage. Microscopy data were supported with transition temperatures and enthalpy
已经合成了包含6-氨基-1,3-二甲基尿嘧啶部分的新的同源的介晶系列。化合物的结构通过元素分析,FT-IR,1 H和13 C NMR光谱技术表征。通过连接到加热台的偏振光学显微镜研究了它们的介晶性质。从差示扫描量热分析获得的转变温度和焓变值支持了显微镜数据。研究表明,化合物的介晶性质取决于烷氧基间隔基的长度。具有较短烷氧基-间隔链(n = 6)的化合物4a-f表现出近晶A相,而化合物4g-r 烷氧基-间隔链(n = 8或10)显示向列相。
Synthesis and phase transition studies of new dimer compounds connected to a 1,3-dimethylbarbituric acid core
作者:AbdulKarim-Talaq MOHAMMAD、Guan-Yeow YEAP、Hasnah OSMAN
DOI:10.3906/kim-1304-51
日期:——
A series of dimeric unsymmetrical liquid crystals derived from heterocyclic 1,3-dimethylbarbituric acid exhibiting smectic A and nematic phase are reported. All compounds were prepared by the condensation of 4'-(R-(4-formylphenoxy)butoxy)biphenyl-4-carboxylate with 1,3-dimethylbarbituric acid in ethanol. The mesomorphic properties were investigated by DSC and POM, where the type of phase depends on the length of spacer alkoxy chains and the length of the terminal chain. While the SmA phase was observed upon the heating and cooling run when the spacer alkoxy chains carbon numbers increased (n = 6), the N phase was observed when the length of spacer alkoxy chains increased (n = 8 and 10).
报道了一系列由杂环 1,3-二甲基巴比妥酸衍生的二聚不对称液晶,具有近晶 A 相和向列相。所有化合物均通过4'-(R-(4-甲酰基苯氧基)丁氧基)联苯-4-羧酸酯与1,3-二甲基巴比妥酸在乙醇中缩合制备。通过DSC和POM研究了介晶性质,其中相的类型取决于间隔烷氧基链的长度和末端链的长度。当间隔烷氧基链碳数增加(n = 6)时,在加热和冷却过程中观察到 SmA 相,而当间隔烷氧基链长度增加(n = 8 和 10)时,观察到 N 相。
Method of producing thermotropic liquid crystalline polyester
申请人:MITSUBISHI CHEMICAL CORPORATION
公开号:EP0520428A2
公开(公告)日:1992-12-30
A thermotropic liquid crystalline polyester is produced by carrying out polycondensation of ester monomer [I-2], an aromatic dicarboxylic acid [II] and an aromatic carboxylic acid [III-2]. The amounts of the compounds [I-2] and [II] are substantially equivalent and the amount of the compound [III-2] is not more than 20 times that of [I-2] by mole. A thermotropic liquid crystalline polyester having good heat resistance, fluidity and uniformity can be produced.