Splitting of Hydrogen Sulfide by Group 14 Elements (Si, Ge, Sn, Pb) in Excess Argon at Cryogenic Temperatures

The water gas reaction C + H₂O → CO + H₂ has been employed for centuries; however little is known for analogous reaction M + H₂S → MS + H₂ (M = Si, Ge, Sn, Pb). In addition, this latter reaction is intriguing in its function of converting pollutant H₂S to clean energy source H₂. We report herein the reactions of laser-ablated Group 14 atom M (M = Si, Ge, Sn, Pb) with H₂S using matrix isolation infrared spectroscopy as well as the state-of-the-art quantum chemical calculations. Important reactive intermediates HMSH with high active H (protonic H^δ+ and hydridic H^δ-) are identified. In addition, the reaction mechanisms are established for insertion reaction M + H₂S → HMSH, and photoinduced H₂ elimination reactions of HMSH → MS+ H₂ and H₂SiS → SiS+ H₂ in low-temperature matrices.