title: Role of Hydrogen Bonding on the Reactivity of Thiyl Radicals: A Mass Spectrometric and Computational Study Using the Distonic Radical Ion Approach.
abstract: Experimental and computational quantum chemistry investigations of the gas-phase ion-molecule reactions between the distonic ions+H3N(CH2)nS•(n = 2-4) and the reagents dimethyl disulfide, allyl bromide, and allyl iodide demonstrate that intramolecular hydrogen bonding can modulate the reactivity of thiyl radicals. Thus, the 3-ammonium-1-propanethiyl radical (n = 3) exhibits the lowest reactivity of these distonic ions toward all substrates. Theoretical calculations on this distonic ion highlight that its most stable conformation involves a six-membered ring configuration, and that it has the strongest intramolecular hydrogen bond. In addition, the calculations indicate that the barrier heights for radical abstraction by this hydrogen-bond-stabilized 3-ammonium-1-propanethiyl radical are the highest among the systems examined, consistent with the experimental observations.
authors.affiliation: School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne , 30 Flemington Rd, Parkville, Victoria 3010, Australia.
authors.forename: Sandra
authors.initials: S
authors.lastname: Osburn
authors.affiliation: Graduate School of Engineering, Nagasaki University , Bunkyo 1-14, Nagasaki 852-8521, Japan.
authors.forename: Bun
authors.initials: B
authors.lastname: Chan
authors.affiliation: Department of Chemistry and Biochemistry and Center for Biochemical and Biophysical studies, Northern Illinois University , Dekalb, Illinois 60115, United States.
authors.forename: Victor
authors.initials: V
authors.lastname: Ryzhov
authors.affiliation: School of Chemistry, University of Sydney , Sydney, NSW 2006, Australia.
authors.forename: Leo
authors.initials: L
authors.lastname: Radom
authors.affiliation: School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne , 30 Flemington Rd, Parkville, Victoria 3010, Australia.
authors.forename: Richard A J
authors.initials: RAJ
authors.lastname: O'Hair