TRIPLET-STATE CIS-TRANS ISOMERIZATIONS OF A BISSTYRYLCYCLOOCTATETRAENE - INEFFICIENT PROCESSES FACILITATING OBSERVATION OF THE INTRINSIC T-1-T-N ABSORPTION-SPECTRA OF THE Z,Z,E,Z, AND E,E ISOMERS

被引：6

作者：

ANGER, I ^{[1
]}

SUNDAHL, M ^{[1
]}

WENNERSTROM, O ^{[1
]}

AUCHTERKRUMMEL, P ^{[1
]}

MULLEN, K ^{[1
]}

机构：

[1] MAX PLANCK INST POLYMER RES,W-6500 MAINZ,GERMANY

来源：

JOURNAL OF PHYSICAL CHEMISTRY | 1995年 / 99卷 / 02期

关键词：

D O I：

10.1021/j100002a032

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The mechanism for triplet-sensitized Z-E isomerizations of Z,Z-, E,Z-, and E,E-1,5-bisstyryl-3,7-dimethyl-cyclooctatetraene (ZZ, EZ, and EE) has been studied by quantum yield measurements and laser flash photolyses. ZZ isomerizes via EZ as a ground-state intermediate to EE with small quantum yields. At the photostationary state the isomer mixture consists of more than 99% EE. The three E,Z isomers have different T-1-T-n, absorption spectra. These results can be explained with a triplet energy surface, with local minima at geometries, in which the noncyclic double bonds are planar. The dominating decay process of (3)ZZ* (3)EZ*, and (3)EE*, is intersystem crossing to the corresponding ground states. Their triplet energies were estimated to be between 40 and 43 kcal mol(-1).

引用

页码：650 / 652

页数：3

共 17 条

[1] TRIPLET-STATE 1-FOLD AND 2-FOLD CIS TRANS ISOMERIZATION OF BISSTYRYLARENES - BALANCE BETWEEN DIABATIC AND ADIABATIC MECHANISMS [J].