Thermochromism at Room Temperature in Overcrowded Bistricyclic Aromatic Enes: Closely Populated Twisted and Folded Conformations
作者:Amalia Levy、Sergey Pogodin、Shmuel Cohen、Israel Agranat
DOI:10.1002/ejoc.200700414
日期:2007.11
The overcrowded thermochromic bistricyclic aromatic enes (BAEs) 10-(9′H-fluoren-9′-ylidene)-9(10H)-anthracenone (6), 10-(11′H-benzo[b]fluoren-11′-ylidene)-9(10H)-anthracenone (7), and 10-(1′,8′-diaza-9′H-fluoren-9′-ylidene)-9(10H)-anthracenone (8) were synthesized by applying Barton's twofold extrusion diazo-thione coupling method and their crystal and molecular structures were determined. BAEs 6–8
过度拥挤的热致变色双三环芳族烯 (BAE) 10-(9'H-芴-9'-亚基)-9(10H)-蒽酮 (6), 10-(11'H-苯并[b]芴-11'- ylidene)-9(10H)-蒽酮 (7) 和 10-(1',8'-diaza-9'H-fluoren-9'-ylidene)-9(10H)-蒽酮 (8) 通过应用合成Barton 的双重挤压重氮-硫酮偶联方法及其晶体和分子结构被确定。由于黄色反折叠构象与热致变色紫色、蓝色或红色扭曲构象之间的平衡,BAE 6-8 在室温下表现出热致变色行为。核磁共振实验证明了溶液中 6-8 的扭曲和反折叠构象异构体的快速互变。BAE 7 容易经历 E,室温下的 Z-拓扑异构化,聚结点为 297 K,能垒相对较低,ΔGc‡(t⟂) = 65.5 kJ/mol。B3LYP/6-311++G(d,p) 计算预测抗折叠的 a-6 和 a-7 比扭曲的 t-6 和 t-7