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。