The quantum chemical study of the electronic states of S2Cl and its monovalent ions.

High-level quantum chemical techniques have been utilized to accurately describe the geometrical parameters, vibrational frequencies and dissociation pathways of the X (2)A″, 1 (2)A', 2 (2)A', 2 (2)A″ states of S(2)Cl; X (1)A', 1 (3)A″, 1 (1)A″, 1 (3)A' states of S(2)Cl(+); X (1)A', 1 (3)A', (1)A″ states of S(2)Cl(-), and the corresponding excitation energies have been obtained from the energies extrapolated to their complete basis set limits. It has been established that the 2 (2)A' and 2 (2)A″ terms of S(2)Cl exhibit a strong multi-reference character, while all the remaining excited states are dominated by the single replacements from the reference determinants. The enthalpies of the decomposition reactions have been obtained to aid in the investigations into the photolysis of S(2)Cl(2) and related systems. The value of the ionization potential of S(2)Cl has been found within the error bars of the experiment, and a reliable estimate of its electron affinity, EA (0) = -2.352 eV, has been proposed.