An investigation into low-lying electronic states of HCS2 via threshold photoelectron imaging

Low-energy photoelectron imaging spectra of HCS(2)(-)are reported for the first time. Vibrationally resolved photodetachment transitions from the ground state of HCS2- to the ground state and low-lying excited states of HCS2 are observed. Combined with the ab intio calculations and Franck-Condon simulations, well-resolved vibrational spectra demonstrate definitive evidence for the resolution of the ground-state and excited states of HCS2 radical in the gaseous phase. The ground state and two low-lying excited states of HCS2 radical are assigned as B-2(2), (2)A(2), and (2)A(1) states, respectively. The adiabatic electron affinity is determined to be 2.910 +/- 0.007 eV. And the term energies of the excited states, T-0 = 0.451 +/- 0.009 eV and 0.553 +/- 0.009 eV, are directly measured from the experimental data, respectively. Angular filtering photoelectron spectra are carried out to assist in the spectral band assignment. (C) 2014 AIP Publishing LLC.