A quantum study on the reaction between C(3P) and acetylene

The reaction between carbon atoms (C(P-3)) and acetylene has been studied by a reduced dimensionality approach, restricted to the initial addition channels, in the energy range between 5 and 70 kJ mol(-1). Coupled cluster calculations with single and double substitution and a non iterative estimate of the triple excitation (CCSD(T)) have been used to generate the lowest triplet potential energy surface. The flux into two different reaction channels, leading to linear and cyclic isomers of C3H, has been calculated by solving the time dependent Schrodinger equation. Results show that linear C3H is preferentially formed, while cyclic C3H is formed only at the highest energy of the calculations. Furthermore, the adiabatic capture-coupled states approximation (ACCSA) has been employed to generate rate constants at low temperatures, using the CCSD(T) potential, giving an improvement on the results obtained by using the long-range part of the potential.