title: Isotope effects in isotope-exchange reactions: evidence for a large 12C/13C kinetic isotope effect in the gas phase.
abstract: The O-exchange reaction between CO2+ and CO is triggered by two different entrance channels in 13C-labeled systems. The unimolecular dissociation of the C13CO3(+) reactive intermediate is investigated at varying energies by mass spectrometric techniques. An almost "one-way" O-exchange at energies close to the dissociation threshold discloses a remarkably large intramolecular 12C/13C kinetic isotope effect ranging from 6.0 to 7.3 +/- 0.5.
authors.forename: Giulia
authors.initials: G
authors.lastname: de Petris
authors.forename: Anna
authors.initials: A
authors.lastname: Troiani
mesh_terms: D002244:Carbon / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry; D002247:Carbon Isotopes / Q000737:chemistry*; D002248:Carbon Monoxide / Q000737:chemistry; D005740:Gases / Q000737:chemistry*; D007700:Kinetics; D013058:Mass Spectrometry; D010100:Oxygen / Q000737:chemistry; D013816:Thermodynamics
chemical_list: D002247:Carbon Isotopes; D005740:Gases; D002245:Carbon Dioxide; C041069:carboxyl radical; D002244:Carbon; D002248:Carbon Monoxide; D010100:Oxygen