Direct measurements of deuterium kinetic isotope effects in anionic, gas-phase substitution and elimination reactions.

摘要: Reactions with dianion nucleophiles were used to determine deuterium kinetic isotope effects (KIE's) in gas-phase E2 and SN2 reactions. This approach allows for the direct identification of elimination substitution products reactions simple alkyl halides. In general, give large KIE's (∼7) perdeutero substrates; however, are attenuated that occur near collision-controlled limit. a very slow elimination, KIE (>20) is observed, presumably due lifetime collision complex. The all secondary unity, exception one system, where suppression channel substrate leads an enhancement rate causes modest inverse effect.