A master equation model for bimolecular reaction via multi-well isomerizing intermediates

A reversible linear master equation model is presented for pressure- and te mperature-dependent bimolecular reactions proceeding via multiple long-live d intermediates. This kinetic treatment, which applies when the reactions a re measured under pseudo-first-order conditions, facilitates accurate and e fficient simulation of the time dependence of the populations of reactants, intermediate species and products. Detailed exploratory calculations have been carried out to demonstrate the capabilities of the approach, with appl ications to the bimolecular association reaction C3H6 + H reversible arrow C3H7 and the bimolecular chemical activation reaction C2H2 +(CH2)-C-1--> C3 H3+H. The efficiency of the method can be dramatically enhanced through use of a diffusion approximation to the master equation, and a methodology for exploiting the sparse structure of the resulting rate matrix is establishe d.