title: Accurate O-H bond dissociation energy differences of hydroxylamines determined by EPR spectroscopy: computational insight into stereoelectronic effects on BDEs and EPR spectral parameters.
abstract: Differences in O-H bond dissociation enthalpies (ΔBDEs) between the hydroxylamine of (15)N-labeled TEMPONE and 10 N,N-di-tert-alkyl hydroxylamines were determined by EPR. These ΔBDEs, together with the g and a(N) values of the derived nitroxide radicals, are discussed in relation to various geometric, intramolecular dipole/dipole, and steric effects and in relation to the results from DFT calculations. We find that dipole/dipole interactions are the dominant factors in dictating a(N) values and O-H BDEs in all of these structurally similar nitroxides and hydroxylamines, respectively. The importance of including the Boltzmann distribution of conformations for each nitroxide in the a(N) calculations is emphasized.
authors.affiliation: Department of Chemistry, University of Ottawa, 10 Marie Curie, Ottawa, ON, Canada K1N 6N5. paulb@photo.chem.uottawa.ca
authors.forename: Paul S
authors.initials: PS
authors.lastname: Billone
authors.forename: Paul A
authors.initials: PA
authors.lastname: Johnson
authors.forename: Shuqiong
authors.initials: S
authors.lastname: Lin
authors.forename: J C
authors.initials: JC
authors.lastname: Scaiano
authors.forename: Gino A
authors.initials: GA
authors.lastname: DiLabio
authors.forename: K U
authors.initials: KU
authors.lastname: Ingold