CONICET | Buscador de Institutos y Recursos Humanos

The five-membered heterocyclic γ-butyrothiolactone was isolated in low temperature inert Ar matrix and the UV-visible (200 ≤ lambda ≤ 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 OVGF/6-311++G(d,p) level of theory. The first three bands at 9.54, 9.69 and 11.89 eV are assigned respectively to the nS and nO and "pi"C=O orbitals, 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 mol1 at the G2MP2 level of calculation within the hyperhomodesmotic model.