TUNABLE VACUUM-ULTRAVIOLET PHOTOFRAGMENT EXCITATION SPECTROSCOPY OF OCS

Photofragment excitation (PHOFEX) spectroscopy of OCS in the vacuum ul traviolet (VUV) has been carried out using tunable VUV excitation of j et-cooled OCS, followed by ultraviolet laser induced fluorescence (LIF ) detection of the S (S-1) photofragment via the S (D-3(1)-S-1) transi tion. The PHOFEX spectrum near 154 nm is better resolved than previous absorption spectra, and new features are visible. The LIF spectrum of the S (S-1) photofragment may be successfully modeled using the produ ct recoil anisotropy (beta=1.8+/-0.2) and CO (upsilon,J) product state distribution previously measured for photodissociation of OCS at 157 nm [Strauss et al., J. Chem. Phys. 90, 5364 (1989)].