title: Matrix photochemistry at low temperatures and spectroscopic properties of gamma-butyrothiolactone.
abstract: The five-membered heterocyclic gamma-butyrothiolactone was isolated in a low-temperature, inert Ar matrix, and the UV-visible (200 <or= lambda <or= 800 nm)-induced photochemistry was studied. On the basis of the IR spectra, the formation of ethylketene (CH(3)CH(2)CH=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 pi(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.
authors: CEQUINOR (UNLP-CONICET, CCT La Plata), Departamento de Química, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, C.C. 962 (1900), La Plata, República Argentina.
authors: Nahir Y
authors: NY
authors: Dugarte
authors: Mauricio F
authors: MF
authors: Erben
authors: Rosana M
authors: RM
authors: Romano
authors: Mao-Fa
authors: MF
authors: Ge
authors: Yao
authors: Y
authors: Li
authors: Carlos O
authors: CO
authors: Della Védova
mesh_terms: D007783:Lactones / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D015394:Molecular Structure; D010777:Photochemistry; D011789:Quantum Theory; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature
chemical_list: D007783:Lactones; C553938:gamma-butyrothiolactone