Reactions of metastable argon with photodissociation aligned carbon disulfide: A study of the steric dependence of two competing reaction channels

CS2 molecules in a beam were aligned using laser photodissociation at 193 nm. Two competing reactions with metastable Ar were studied as a function of CS2 alignment. The Penning ionization reaction cross section for formation of CS+2 (X 2Πg) was found to be largest when the CS2 bond is parallel to the relative velocity vector, while the cross section for dissociative excitation giving CS*(A 1Π) is largest when the CS2 bond is perpendicular to the relative velocity vector.