AN ABINITIO STUDY OF C2S PROTONATION

An ab initio study of the structures and stabilities of (SC2H)+ isomers has been carried out at the Hartree-Fock and Moller-Plesset levels of theory. A linear SCCH+ species (3-SIGMA-) is found to be the ground state at all levels of theory. This species, a possible precursor of SC2 recently detected in the interstellar medium, has a dipole moment high enough to allow its detection if present in space. The estimated proton affinity of SC2 is high, about 215 kcal/mol at the projected third-order Moller-Plesset level.