Thermochemical stabilities and structures of the gas-phase cluster ions of halide ions with OCS

Abstract

Gas-phase clustering reactions of halide ions with carbonyl sulfide were studied using a pulsed electron-beam mass spectrometer. For F −, formation of a stable FCSO − species was found with the F −–CSO binding energy of >30 kcal/mol (the calculated value=33.41 kcal/mol). DFT calculations showed that the three-fold in-plane coordination to the n=1 species is stable. For Cl −, Br − and I −, the bond energies of cluster ions are in the range of 5–10 kcal/mol with symmetric geometries. All cluster geometries except for F − with n=1 are controlled by the σ ∗ vacant orbital of OCS with participation of the sulfur 3d z 2−( x 2+ y 2) atomic orbital.