Theoretical studies of the gas-phase pyrolysis kinetics of ω-bromonitriles, ZCH2CH2Br [Z = NC, NCCH 2, NCCH2CH2]

Abstract:

The gas-phase elimination of several ω-bromonitriles (ZCH <inf>2</inf>CH<inf>2</inf>Br, Z = NC, NCCH<inf>2</inf>, NCCH<inf>2</inf>CH <inf>2</inf>) has been examined at the MP2/6-31G(d,p), MP2/6-31G(2d,2p), B3PW91/6-31G(2d,2p), and MPW91PW91/6-31(2p,2d) levels of theory. The bromonitriles yield the corresponding cyano-olefin and HBr gas in a rate-determining step. The MPW91PW91/6-31G(2p,2d) results suggest a concerted mechanism, with a polar, four-membered transition state. The calculated kinetic and thermodynamic parameters were found to be within reasonable agreement with the experimental determinations. Substituent effects are discussed in terms of electronic structure. © 2008 Wiley Periodicals, Inc.

Año de publicación:

2009

Keywords:

Fuente:

scopus