Heavy atom nitroxyl radicals. IV. Experimental and theoretical studies of the F2P=S free radical in the gas phase

The difluorothiophosphoryl F2PS free radical has been produced in a supersonic discharge jet from a precursor mixture of F3PS and high pressure argon and detected by laser-induced fluorescence and single vibronic level emission spectroscopy. With the aid of high level ab initio predictions of the properties of the ground and first two excited doublet states, the observed band system has been positively identified as B2A'-X2A'. The electronic transition involves promotion of an electron from the to the orbital with concomitant increases in the out-of-plane angle and PS bond length on excitation. The observed vibrational structure, Franck–Condon profile, rotational band contours, T0 energy, and ground and excited state vibrational frequencies are all in accord with expectations based on our theoretical predictions.