Theoretical and experimental investigation of the C2H + SO2 reaction over the range T = 295–800 K

Absolute rate constants for the gas-phase reaction C2H + SO2 are experimentally determined over the temperature range 295–800 K. C2H radicals are generated by pulsed 193-nm photolysis of C2H2 in the presence of SO2 and He or N2 buffer gas. The temperature dependence of the rate constants is established as k SO 2 (T) = (0.86 ± 0.08) T3.80±0.13 exp[−(1222 ± 79)/T] cm3 s−1. The rate constants are moderately high at these temperatures and show negative temperature dependence. CCSD(T)/6-311++G(3df,2p) calculations of the potential energy surface confirm experimental findings and show that the reaction products are HCCO + SO.