Spin-orbit Ab initio investigation of the photodissociation of dibromomethane in the gas and solution phases

✍ Scribed by Yajun Liu; Hongyan Xiao; Mengtao Sun; Weihai Fang

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 266 KB
• Volume: 29
• Category: Article
• ISSN: 0192-8651
• DOI: 10.1002/jcc.21008

✦ Synopsis

Abstract

A clear and reliable theoretical investigation on dibromomethane (CH~2~Br~2~) photodissociation is desired. The calculation must consider: (i) relativistic effects; (ii) the potential energy curves (PECs) of spin‐orbit coupling states; (iii) geometry optimization by the method with both static and dynamic electron correlations; (iv) solvent effects on the photodissociation in the solution. All these have been considered in this study by state‐of‐the‐art quantum chemical calculations. The experimentally observed photodissociation in the gas phase with products of spin‐orbit‐coupled states, Br(^2^P~3/2~) and Br*(^2^P~1/2~), was assigned by multi‐state second order multiconfigurational perturbation theory in conjunction with spin‐orbit interaction through complete active space state interaction (MS‐CASPT2/CASSI‐SO) PECs. The mechanisms of the experimentally observed photodissociation and photoisomerization in solvent were elucidated by the MS‐CASPT2/CASSI‐SO method combined with polarized continuum model of the solvent. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2008