Fermi resonance and strong anharmonic effects in the absorption spectra of the ν-OH (ν-OD) vibration of solid H- and D-benzoic acid |
| |
Authors: | A.M. Yaremko H. Ratajczak A.J. Barnes J. Baran P. Durlak Z. Latajka |
| |
Affiliation: | aInstitute of Semiconductor Physics of the National Academy of Sciences of Ukraine, 45 Prospect Nauki, Kiev 03028, Ukraine;bFaculty of Chemistry, University of Wrocław, ul. F. Joliot-Curie 14, 50-383 Wrocław, Poland;cInstitute of Materials Research, University of Salford, Salford M5 4WT, UK;dInstitute of Low Temperature and Structure Research of the Polish Academy of Sciences, 50-950 Wrocław 2, P.O. Box 937, Poland |
| |
Abstract: | The vibrational spectra of polycrystalline benzoic acid (BA) and its deuterated derivative were studied over the wide frequency region 4000–10 cm−1 by IR and Raman methods. A theoretical analysis of the hydrogen bond frequency region and calculations at the B3LYP/6-311++G(2d, 2p) level for the benzoic acid cyclic dimer in the gas phase were made. In order to study the dynamics of proton transfer two formalisms were applied: Car–Parrinello Molecular Dynamics (CPMD) and Path Integrals Molecular Dynamics (PIMD). It was shown that the experimentally observed very broad ν-OH band absorption is the result of complex anharmonic interaction: Fermi resonance between the OH-stretching and bending vibrations and strong interaction of the ν-OH stretching with the low frequency phonons. The theoretical analysis in the framework of such an approach gave a good correlation with experiment. From the CPMD calculations it was confirmed that the O–HO bridge is not rigid, with the OO distance being described by a large amplitude motion. For the benzoic acid dimer we observed stepwise (asynchronous) proton transfer. |
| |
Keywords: | Infrared spectra Hydrogen bond Fermi resonance Anharmonic interaction Proton transfer |
本文献已被 ScienceDirect 等数据库收录! |
|