## Abstract

We present calculations of the rate constants and secondary kinetic isotope effects for the gas-phase S_{N}2 reaction Cl^{-}(H _{2}O)+CH_{3}Cl based on a new chloride-water potential-energy function that has been specifically converged for heavy-water isotope effects. The results are compared to new calculations employing five chloride-water potential-energy functions that have been developed for simulations of aqueous solutions. In all calculations the ClCH_{3}Cl^{-} solute intramolecular potential is taken from a previous semiglobal fit to ab initio calculations including electron correlation. We also examine two different intramolecular water potentials, and we examine the effect of treating the CH_{3} internal rotation at the ClCH_{3}Cl^{-}(H _{2}O) transition state as a hindered rotation. Both the CH _{3}/CD_{3} (α-deuterium) and H_{2}O/D _{2}O (microsolvation) kinetic isotope effects are studied.

Original language | English (US) |
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Pages (from-to) | 6369-6383 |

Number of pages | 15 |

Journal | The Journal of Chemical Physics |

Volume | 97 |

Issue number | 9 |

DOIs | |

State | Published - Jan 1 1992 |

## ASJC Scopus subject areas

- Physics and Astronomy(all)
- Physical and Theoretical Chemistry