Gas-phase chemical models of interstellar molecular clouds

A large gas-phase chemical model of interstellar molecular clouds containing almost 4,000 gas-phase reactions involving 409 species are developed. The calculated results are in excellent agreement with observed abundances in TMC1.;The effects of rapid neutral-neutral reactions in the gas phase on the synthesis of complex species is studied via a series of model calculations. Reactions between O or N atoms and carbon clusters C;Bistability in large gas-phase chemical networks of dense clouds is examined. The dependence of bistability on the parameter ;A model of time-dependent gas-phase chemistry in a spatially inhomogeneous cloud which is exposed on one side to an isotropic radiation field is presented. Shielding due to H...