Crystalline-State <i>Z,E-</i>Photoisomerization of a Series of (<i>Z</i>,<i>E</i>,<i>Z</i>)-1,6-Diphenylhexa-1,3,5-triene 4,4‘-Dicarboxylic Acid Dialkyl Esters. Chain Length Effects on the Crystal Structure and Photoreactivity
作者:Yoriko Sonoda、Yuji Kawanishi、Seiji Tsuzuki、Midori Goto
DOI:10.1021/jo051137g
日期:2005.11.1
series of (Z,E,Z)-1,6-diphenylhexa-1,3,5-triene 4,4‘-dicarboxylic acid dialkyl (R) esters [(Z,E,Z)-1a, R = Me; (Z,E,Z)-1b, R = Et; (Z,E,Z)-1c, R = n-Pr; (Z,E,Z)-1d, R = n-Bu] was investigated. All Z,E,Z isomers underwent one-way isomerization to the corresponding E,E,E isomers. The reaction efficiency was strongly enhanced as the length of the alkyl chain increased. Single-crystal X-ray analyses of (Z
结晶状态Ž,Ë一系列(的-photoisomerization Ž,ê,Ž)-1,6- diphenylhexa -1,3,5-三烯-4,4'-二羧酸二烷基(R)酯[(Ž,ê,Z)-1a,R = Me; (Z,E,Z)-1b,R = Et; (Z,E,Z)-1c,R =n- Pr;(Z,E,Z)-1d,R =n- Bu]被研究。全部Z,E,Z异构体经过单向异构化为相应的E,E,E异构体。随着烷基链长度的增加,反应效率大大提高。(Z,E,Z)-1a - d的单晶X射线分析表明,晶体的烷基链部分随着链长的增加而变大。烷基链的构象柔韧性使晶格中三烯几何结构发生较大变化成为可能,从而导致了晶态下光反应性的增强。