The sulfur reaction in small ionized carbonyl sulfide clusters

Ionic species obtained by electron impact on (OCS)n clusters produced by expansion of OCS mixed with argon at two different (OCS/argon) concentrations are studied as a function of stagnation pressure and electron energy. Ionization efficiency curves of homogeneous cluster ions (OCS)+n, homogeneous sulfur cluster ions S+m and inhomogeneous ions (OCS)nS+m are analyzed. Several reactions paths, ending in S+m, have been identified. The strong correlation between reaction path and cluster size is discussed. Finally, by minimization of the potential function created by dipole–dipole, dipole–quadrupole, and quadrupole–quadrupole interactions between OCS molecules, we propose the geometrical configurations of neutral (OCS)n (n=2–5) clusters.