title: [1 + 1] photodissociation of CS(2)(+)(X̃2Π(g)) via the vibrationally mediated B̃2Σ(u)+ state: multichannels exhibiting and mode specific dynamics.
abstract: Dissociation dynamics of CS(2)(+) vibrationally mediated via its B̃(2)Σ(u)(+) state, was studied using the time-sliced velocity map imaging technique. The parent CS(2)(+) cation was prepared in its X̃(2)Π(g) ground state through a [3 + 1] resonance enhanced multiphoton ionization process, via the 4pσ(3)Π(u) intermediate Rydberg state of neutral CS(2) molecule at 483.14 nm. CS(2)(+)(X̃(2)Π(g)) was dissociated by a [1 + 1] photoexcitation mediated via the vibrationally selected B̃ state over a wavelength range of 267-283 nm. At these wavelengths the C̃(2)Σ(g)(+) and D̃(2)Σ(u)(+) states are excited, followed by numerous S(+) and CS(+) dissociation channels. The S(+) channels specified as three distinct regions were shown with vibrationally resolved structures, in contrast to the less-resolved structures being presented in the CS(+) channels. The average translational energy releases were obtained, and the S(+)∕CS(+) branching ratios with mode specificity were measured. Two types of dissociation mechanisms are proposed. One mechanism is the direct coupling of the C̃ and D̃ states with the repulsive satellite states leading to the fast photofragmentation. The other mechanism is the internal conversion of the C̃ and D̃ states to the B̃ state, followed by the slow fragmentation occurred via the coupling with the repulsive satellite states.
authors.affiliation: Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, People's Republic of China.
authors.forename: Jialin
authors.initials: J
authors.lastname: Li
authors.forename: Cuimei
authors.initials: C
authors.lastname: Zhang
authors.forename: Qun
authors.initials: Q
authors.lastname: Zhang
authors.forename: Yang
authors.initials: Y
authors.lastname: Chen
authors.forename: Cunshun
authors.initials: C
authors.lastname: Huang
authors.forename: Xueming
authors.initials: X
authors.lastname: Yang