Collision-induced dissociation dynamics of the [OCS • C2H2]+ complex. A combined experimental and theoretical study

Collision-induced dissociation (CID) of the [OCS • C2H2]+ complex ion with both Xe and Ar over an energy range of 0 to 10 eV in the center of mass frame is studied using a guided ion beam tandem mass spectrometer. The cross sections of the ionic products observed (C,H2S+, OCS+, C2HJ, and S+) are analyzed by taking into account reactant energy distributions, multiple collisions, lifetime effects and competition. A recently devised statistical model for the simultaneous analysis of competitive product channels is used to analyze three channels for the first time, with good results. Thresholds for product formation at 0 Kelvin are 0.33+0.07 eV for C2H2S+, 0.95+0.07 eV for OCS+, 1.22+0.08 eV for C2H,, and an upper limit of 4.26 eV for S+.