PHOTODESTRUCTION SPECTROSCOPY OF CARBON-DISULFIDE CLUSTER ANIONS (CS2)(N)(-) N=1-4 - EVIDENCE FOR THE DIMER CORE STRUCTURE AND COMPETITIVE REACTIONS OF THE DIMER ANION

Photodestruction spectra of carbon disulfide cluster anions, (CS2)(n)( -),, n=1-4, have been measured with a time-of-flight mass spectrometer coupled with an optical parametric oscillator. The spectra of all the cluster anions of n greater than or equal to 2 were found to exhibit a similar absorption band peaking at 1.6-1.8 eV, suggesting that a C2S 4-, core is involved in the cluster anions. Photon energy, dependence of competition between electron detachment and dissociation:ion of the dimer anion was also observed. It was found that there is a reaction channel of the dimer anion producing C2S2-, and S-2, as well as the or dinary dissociation into CS2- and CS2. The most stable form of the dim er anion was investigated by nb initio calculations at the unrestricte d Hartree-Fock/6-31+G level, showing that the stable form involves co valent C-C and S-S bonds. Reaction:n mechanisms are discussed on the b asis of electronic symmetries of the parent and the fragments. (C) 199 5 American Institute sf Physics, [S0021-9606(98)01804-2].