Brause Robert, Santa Monika, Schmitt Michael, Kleinermanns Karl
Heinrich-Heine-Universität, Institut für Physikalische Chemie I, 40225 Düsseldorf, Germany.
Chemphyschem. 2007 Jun 25;8(9):1394-401. doi: 10.1002/cphc.200700127.
The change of the phenol dimer (PH2) structure upon electronic excitation is determined by a Franck-Condon analysis of the intensities in the fluorescence emission spectra obtained via excitation of seven different vibronic bands. A total of 547 emission band intensities are fitted, together with the changes of rotational constants upon electronic excitation of fi ve isotopomers. These rotational constants are taken from previously published [Schmitt et al. ChemPhysChem 2006, 7, 1241-1249] high-resolution LIF measurements. The geometry change upon electronic excitation of the pipi* state of the donor moiety can be described by a strong shortening of the hydrogen bond, a shortening of the CO bond in the donor moiety, an overall symmetric expansion of the donor phenol ring, and a nearly unchanged acceptor moiety. The resulting geometry changes are interpreted on the basis of ab initio calculations.
通过对七个不同振转带激发所获得的荧光发射光谱强度进行弗兰克-康登分析，确定了电子激发后酚二聚体（PH2）结构的变化。总共拟合了547个发射带强度，以及五种同位素异构体电子激发后转动常数的变化。这些转动常数取自先前发表的[施密特等人，《化学物理化学》2006年，7卷，1241 - 1249页]高分辨率激光诱导荧光测量结果。供体部分ππ*态电子激发时的几何结构变化可描述为氢键强烈缩短、供体部分C - O键缩短、供体酚环整体对称扩张以及受体部分几乎不变。基于从头算计算对所得的几何结构变化进行了解释。
