甲酸第四泛频OH伸缩振动光谱中的共振耦合

Resonance coupling in the fourth OH-stretching overtone spectrum of formic acid.

作者信息

Howard Daryl L, Kjaergaard Henrik G

机构信息

Department of Chemistry, University of Otago, P.O. Box 56, Dunedin, New Zealand.

出版信息

J Chem Phys. 2004 Jul 1;121(1):136-40. doi: 10.1063/1.1753555.

DOI:10.1063/1.1753555

PMID:15260530

Abstract

The room-temperature vibrational overtone spectra of the formic acid isotopomers HCOOH and DCOOH have been recorded in the third and fourth OH-stretching overtone regions with intracavity laser photoacoustic spectroscopy. Resonance coupling between the OH- and CH-stretching vibrations in HCOOH is clearly identified in the fourth overtone region. This is an example of strong coupling across bonds. In the third overtone region, no resonance is observed. Vibrational energies and intensities of the OH- and CH-stretching overtones and combination bands have been calculated with an anharmonic oscillator local mode model. The pure OH-stretching bright state carries almost all the intensity prior to resonance coupling.

摘要

利用腔内激光光声光谱技术，记录了甲酸同位素异构体HCOOH和DCOOH在第三和第四OH伸缩泛音区域的室温振动泛音光谱。在第四泛音区域清晰地识别出了HCOOH中OH和CH伸缩振动之间的共振耦合。这是一个跨键强耦合的例子。在第三泛音区域，未观察到共振。利用非谐振荡器局域模模型计算了OH和CH伸缩泛音及组合带的振动能量和强度。在共振耦合之前，纯OH伸缩亮态几乎承载了所有的强度。