Proton-held dimer and trimer of carbon disulfide

Abstract

The gas-phase clustering reactions H +CS 2(CS 2) n−1 +CS 2→H +CS 2(CS 2) n ( n= 1, 2) were studied using a pulsed electron beam high-pressure mass spectrometer. The measured bond energies of H +CS 2(CS 2) n with n= 1 and 2 are found to be considerably smaller than those of H +CO 2(CO 2) n measured previously in our laboratory. The cluster ions H +CS 2(CS 2) n have the proton-held dimer cation H +CS 2(CS 2) 1 as a core ion, i.e. H +CS 2(CS 2) 1…(CS 2) n−1 . The geometries and binding energies of H +CS 2(CS 2) n and H +CO 2(CO 2) n with n=0–2 were determined by ab initio MO calculations. The most stable structure of H +CS 2(CS 2) 1…CS 2 has an out-of-plane geometry while that of H + CO 2(CO 2) 1…CO 2 has an in-plane one. The nature of bonding of the cluster ions may be explained by frontier-orbital interactions.