PHOTODISSOCIATION OF S2CL2 : STATE-SPECIFIC DETECTION OF ATOMIC AND MOLECULAR SULPHUR

Abstract Disulphur dichloride (S 2 Cl 2 ) 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, S 2 and S. In the case of the S 2 molecule, information on relative vibrational and rotational distributions is obtained. Both internal degrees of freedom are characterized by Boltzmann-type distributions, with temperatures of T rot =1000(500) K and T vib =450(100) K. Knowledge of these distributions allows a reconstruction of the state-independent relative S 2 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 S 2 Cl 2 parent molecule between 36000 and 39000 cm −1 . For higher energies, the absorption signal significantly exceeds the overall yield of the S 2 - and S-producing channels, thus revealing that further channels open in that region. An overview regarding the dissociation products of S 2 Cl 2 is presented for the energy region between 28000 and 41500 cm −1 . Features appearing on the low-energy edge of the experimental atomic sulphur yield spectra are analyzed and interpreted in terms of transition state theory.