Resonance-enhanced two-photon ionization mass spectroscopy of ephedrine:: Indication for a state-selective fragmentation in a flexible molecule

被引：8

作者：

Karaminkov, R. ^{[1
]}

Chervenkov, S. ^{[1
]}

Haerter, P. ^{[1
]}

Neusser, H. J. ^{[1
]}

机构：

[1] Tech Univ Munich, D-85748 Garching, Germany

来源：

CHEMICAL PHYSICS LETTERS | 2007年 / 442卷 / 4-6期

关键词：

D O I：

10.1016/j.cplett.2007.05.111

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 vibronic structure of the S-1 <- S-0 spectrum of ephedrine was measured by resonance-enhanced two-photon ionization spectroscopy with mass resolution under cold molecular beam conditions. The spectra recorded at four different mass channels, m/z = 165 (parent), 58, and the hitherto unknown 71, 85 fragment ions show dissimilar vibronic fine structure and the observed mass pattern strongly depends on the selected intermediate vibrational state. This points to an intermediate state-selected process resulting in a different fragmentation mass pattern. Ab initio calculations at the MP2/6-311++G** level demonstrate that the AG (a) conformer is more stable by 238 cm(-1) than the next stable GG (a) conformer. (c) 2007 Elsevier B.V. All rights reserved.

引用

页码：238 / 244

页数：7

共 21 条

[1] STRUCTURE AND FRAGMENTATION MECHANISMS OF SOME IONS IN MASS-SPECTRUM OF EPHEDRINE [J].