PHOTODISSOCIATION OF S2CL2 - STATE-SPECIFIC DETECTION OF ATOMIC AND MOLECULAR SULFUR

Disulphur dichloride (S2Cl2) is dissociated by tunable laser radiation in the region of 36000 to 41500 cm(-1). By using LIF and REMPI TOF de tection techniques, state-resolved detection is achieved for both prod ucts, S-2 and S. In the case of the S-2 molecule, information on relat ive vibrational and rotational distributions is obtained. Both interna l degrees of freedom are characterized by Boltzmann-type distributions , with temperatures of T-rot = 1000(500) K and T-vib =450(100) K. Know ledge of these distributions allows a reconstruction of the state-inde pendent relative S-2 yield in the investigated region. Similarly, rela tive yield measurements for S are performed for a second dissociation channel. For both channels, energy-dependent absolute cross sections a re derived which result in excellent agreement between the combined yi eld of both channels and the total absorption spectrum of the S2Cl2 pa rent 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 i n that region. An overview regarding the dissociation products of S2Cl 2 is presented for the energy region between 28000 and 41500 cm(-1). F eatures appearing on the low-energy edge of the experimental atomic su lphur yield spectra are analyzed and interpreted in terms of transitio n state theory. (C) 1998 Published by Elsevier Science B.V.