Substitution effect on the photochromic properties of benzo[b]thiophene-1,1-dioxide based diarylethenes
作者:Shangjun Chen、Wenlong Li、Xin Li、Wei-Hong Zhu
DOI:10.1039/c5ra18116j
日期:——
containing methyl, phenyl, formyl and triphenylamine groups at the 5,5′-position of the thiophene rings have been developed for gaining an insight into the substituent effect on the absorption and photochromic properties. Electron-donating substituents, such as phenyl and triphenylamine groups, are found to be effective at shifting the absorption band to a longer wavelength and decreasing the cyclization
已经开发出苯并[ b ]噻吩-1,1-二氧化物二芳基醚(DAE),BTT-1至BTT-4,在噻吩环的5,5'-位上含有甲基,苯基,甲酰基和三苯胺基,用于了解取代基对吸收和光致变色特性的影响。发现给电子的取代基,例如苯基和三苯胺基,可有效地将吸收带移至更长的波长并降低环化量子产率。吸电子的甲酰基可提高环化量子产率,但在一定程度上降低了闭环异构体的热稳定性。BTT-4带有三苯胺基团的化合物显示出这四种化合物中最差的抗疲劳性,这可能是由于闭环异构体中更大的π共轭延伸长度所致。带有苯基单元的BTT-2不仅在溶液中经历典型的光致变色反应,而且在PMMA薄膜中以及在具有出色的抗疲劳性和热稳定性的大体积晶体中也经历典型的光致变色反应。