Matrix Photochemistry at Low Temperatures and Spectroscopic Properties of γ-Butyrothiolactone

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• 作者：Nahir Y. Dugarte ; Mauricio F. Erben ; Rosana M. Romano ; Mao-Fa Ge ; Yao Li ; Carlos O. Della Vdova
• 刊名：Journal of Physical Chemistry A
• 出版年：2010
• 出版时间：September 9, 2010
• 年：2010
• 卷：114
• 期：35
• 页码：9462-9470
• 全文大小：295K
• 年卷期：v.114,no.35(September 9, 2010)
• ISSN：1520-5215

文摘

The five-membered heterocyclic γ-butyrothiolactone was isolated in a low-temperature, inert Ar matrix, and the UV−visible (200 ≤ λ ≤ 800 nm)-induced photochemistry was studied. On the basis of the IR spectra, the formation of ethylketene (CH₃CH₂CH═C═O) was identified as the main channel of photodecomposition. The valence electronic structure was investigated by He(I) photoelectron spectroscopy assisted by quantum chemical calculations at the outer valence Green’s function/6-311++G(d,p) level of theory. The first three bands at 9.54, 9.69, and 11.89 eV are assigned to the n_S, n_O, and π_C═O orbitals, respectively, denoting the importance of the −SC(O)− group in the outermost electronic properties. The conventional ring strain energy was determined to be 3.8 kcal mol⁻¹ at the G2MP2 level of calculation within the hyperhomodesmotic model.