Theoretical study of reactions between AlH(1?) and HF molecule

Abstract

Reaction mechanisms between AlH (1Σ) and HF molecule are theoretically investigated. Ab initio calculations demonstrate that there are two parallel reaction channels: one is an addition reaction to give H2AlF via the three-membered ring transition state (TS) and the other is a dehydrogenation reaction to give AlF+H2 via the four-membered ring TS. The addition reaction is thermodynamically favorable and the dehydrogenation reaction is kinetically favorable. Thermodynamics and Eyring transition state theory (TST) with the Wigner correction are also used to compute the thermodynamic functions, the equilibrium constants, A factors, and the rate constants of these reaction channels at 200–1000 K. From the thermodynamics and TST calculations, it is valuable to point out that consideration on the entropy and thermal enthalpy is quite important in the study of chemical reactions on the basis of ab initio method. ©1999 John Wiley & Sons, Inc. Int J Quant Chem 73: 417–424, 1999