偶氮苯光异构化的机制与动力学

Mechanism and dynamics of azobenzene photoisomerization.

作者信息

Schultz Thomas, Quenneville Jason, Levine Benjamin, Toniolo Alessandro, Martínez Todd J, Lochbrunner Stefan, Schmitt Michael, Shaffer James P, Zgierski Marek Z, Stolow Albert

机构信息

Steacie Institute for Molecular Sciences, National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario, Canada K1N 0R6.

出版信息

J Am Chem Soc. 2003 Jul 9;125(27):8098-9. doi: 10.1021/ja021363x.

DOI:10.1021/ja021363x

PMID:12837068

Abstract

The excited-state dynamics of trans-azobenzene were investigated by femtosecond time-resolved photoelectron spectroscopy and ab initio molecular dynamics. Two near-degenerate pipi* excited states, S2 and S3,4, were identified in a region hitherto associated with only one excited state. These results help to explain contradictory reports about the photoisomerization mechanism and the wavelength dependence of the quantum yield. A new model for the isomerization mechanism is proposed.

摘要

通过飞秒时间分辨光电子能谱和从头算分子动力学研究了反式偶氮苯的激发态动力学。在一个迄今为止仅与一个激发态相关的区域中，确定了两个近简并的ππ*激发态，即S2和S3,4。这些结果有助于解释关于光异构化机制和量子产率的波长依赖性的相互矛盾的报道。提出了一种异构化机制的新模型。