Isotope separation in chemical reactions of vibrationally excited molecules

The vibrations] distribution functions are analyzed theoretically for a binary mixture of diatomic gases modeled by anharmonic oscillators. It is assumed that the conditions are far from equilibrium. The results are used to calculate the isotope separation coefficient for chemical reactions involving vibrationally excited molecules. It is shown that far from equilibrium the separation coefficient is no longer an exponential function of the ratio of the activation energy to the gas temperature but depends only on the nonequilibrium store of the vibrational energy of the system.