Theoretical study of the reaction of P+ with methane

The dynamics of the reaction of P+ with methane were studied by means of a combination of an approximate classical trajectory method and RRKM theory, using accurate ab initio computations of the relevant minima and saddle points of the lowest singlet and triplet potential energy surfaces. The results were compared with those of gas-phase experiments obtained at 300 K. Computed rate coefficients are given for a wide range of temperatures from 40 to 1000 K and may be useful in the modelling of interstellar chemistry, where the reaction of P+ with methane is believed to play a crucial role in the synthesis of small molecules containing a P-C bond. The results appear to imply that an intersystem crossing process may play a key role in the reaction dynamics.