The chlorosulfanyl thiocyanate molecule, ClSSCN, was generated in the gas phase through heterogeneous reaction
of SCl2 on the surface of finely powdered AgSCN for the first time. The reaction products were detected and
characterized in situ by ultraviolet photoelectron and photoionization mass spectrometry. The molecular geometry
and electronic structures of ClSSCN were investigated by a combination of PES experiment and theoretical calculations
with the density functional theory and ab initio methods. It was found that the outermost electrons of ClSSCN
reside in the Cl−S antibonding π orbital, predominantly localized on the sulfur atom, and the experimental first
vertical ionization potential of ClSSCN is 10.20 eV. The dominant fragment SSCN+ in the mass spectrum indicates
that the ClSSCN cation prefers the dissociation of the Cl−S bond