Dissociative ionisation of CS2 and the formation of S-2(+)

Photoelectron-photoion coincidence spectroscopy has been used to examine di ssociative ionisation of CS2 from electronic states of CS: up to 27 eV, inc luding the satellite states 3, 4, 6 and 10 whose decay has not been studied before. Branching ratios to the ions S+, CS+, S-2(+) and C+ have been dete rmined throughout the range and kinetic energy release distributions have b een deduced from peak shapes, allowing inferences on the states of the frag ments. The choice of product channel is not strongly dependent on initial p arent ion state identity. The products are formed in many different final s tates, but kinetic energy releases less than 3 eV are favoured, correspondi ng to formation of highly excited states of the products. In confirmation, optical emission has been found in coincidence with photoelectrons from for mation of several inner valence states of the ions. Formation of S-2(+) occ urs from several initial states of the parent ion and possible mechanisms a re considered. It is concluded that a "quasi-statistical'' model may best d escribe the dissociation of CS: from the inner valence states. (C) 2001 Els evier Science B.V. All rights reserved.