Photodissociation of S2Cl2: state-specific detection of atomic and molecular sulphur Original Research Article

Disulphur dichloride (S2Cl2) is dissociated by tunable laser radiation in the region of 36000 to 41500 cm−1. By using LIF and REMPI TOF detection techniques, state-resolved detection is achieved for both products, S2 and S. In the case of the S2 molecule, information on relative vibrational and rotational distributions is obtained. Both internal degrees of freedom are characterized by Boltzmann-type distributions, with temperatures of Trot=1000(500) K and Tvib=450(100) K. Knowledge of these distributions allows a reconstruction of the state-independent relative S2 yield in the investigated region. Similarly, relative yield measurements for S are performed for a second dissociation channel. For both channels, energy-dependent absolute cross sections are derived which result in excellent agreement between the combined yield of both channels and the total absorption spectrum of the S2Cl2 parent molecule between 36000 and 39000 cm−1. For higher energies, the absorption signal significantly exceeds the overall yield of the S2- and S-producing channels, thus revealing that further channels open in that region. An overview regarding the dissociation products of S2Cl2 is presented for the energy region between 28000 and 41500 cm−1.