The Δ2,2′-Bi(2H-1,4-benzothiazine) Structural Motif of Red Hair Pigments Revisited: Photochromism and Acidichromism in a Unique Four-State System
作者:Loredana Leone、Orlando Crescenzi、Alessandra Napolitano、Vincenzo Barone、Marco d'Ischia
DOI:10.1002/ejoc.201200673
日期:2012.9
Complete spectral and computational characterization of Δ2,2′-bi(2H-1,4-benzothiazine) (BBTZ) demonstrated that the structures of the stable yellow form and the photogenerated red form were assigned incorrectly and should be revised to the cis (Z) and trans (E) isomers, respectively. A blue elusive dication generated upon further protonation of the violet cationic form was also identified by UV spectroscopy
Δ2,2'-bi(2H-1,4-benzothiazine) (BBTZ) 的完整光谱和计算表征表明,稳定的黄色形式和光生红色形式的结构分配不正确,应修改为顺式 (Z ) 和反式 (E) 异构体。还通过紫外光谱和 DFT 计算确定了在紫色阳离子形式进一步质子化时产生的蓝色难以捉摸的指示。基于这些数据,BBTZ 可以被视为适用于各种应用的强大的四态系统。