The derivatives of 1-phenyl-2-(2-thienyl)-5-[5-(tricyanoethenyl)-2-thienyl]pyrrole (1a) formed crystals with gold-like or bronze-like metallic luster. When a small substituent is located at the para position of the 1-phenyl group, gold-like lustrous crystals were formed. In contrast, the derivatives of 1 having a longer alkyl chain at the para position of the 1-phenyl group gave bronze-like crystals. The gold-like lustrous crystals have a sheet structure. In the sheet, the molecules of 1 are close to each other via the intermolecular interaction of cyano nitrogen with the hydrogen of the nearest thiophene or pyrrole ring, which enables the side-by-side interaction of the cyano group with the nearest thiophene and pyrrole rings. The bronze-like crystals have a lamella structure of the long alkyl chains that is sandwiched by two π-electron walls. In the wall, the 2-(2-thienyl)-5-[5-(tricyanoethenyl)-2-thienyl]pyrrole moieties are arranged in a ribbon structure to interact to each other. The relationship of the arrangement of the 2-(2-thienyl)-5-[5-(tricyanoethenyl)-2-thienyl]pyrrole moieties with the metallic color of the crystals is discussed.
1- 苯基-2-(2-
噻吩基)-5-[5-(三
氰基
乙烯基)-2-
噻吩基]
吡咯(1a)的衍
生物形成了具有
金色或青
铜色
金属光泽的晶体。如果在 1-苯基的对位上添加一个小取代基,则会形成具有
金色光泽的晶体。相反,在 1-苯基的对位上具有较长烷基链的 1 的衍
生物则会形成古
铜色晶体。类
金色光泽晶体具有片状结构。在片状结构中,1 的分子通过
氰基氮与最近的
噻吩环或
吡咯环的氢的分子间相互作用而彼此靠近,从而使
氰基与最近的
噻吩环和
吡咯环并排相互作用。青
铜晶体具有长烷基链的薄片结构,被两个 π 电子壁夹在中间。在壁中,2-(2-
噻吩基)-5-[5-(三
氰基
乙烯基)-2-
噻吩基]
吡咯分子以带状结构排列,相互影响。本文讨论了 2-(2-
噻吩基)-5-[5-(三
氰基
乙烯基)-2-
噻吩基]
吡咯分子的排列与晶体
金属色的关系。