title: Synthesis and Characterization of a Nitroxide-Semiquinone Biradical.
abstract: The synthesis and characterization of an anion biradical, 1(-)(*)(*), composed of semiquinone and nitroxide functionalities is described. The biradical was prepared by reduction of the nitroxide-orthoquinone precursor using both electrochemical and chemical methods. The zero-field-splitting parameter, |D/hc|, for 1(-)(*)(*) is consistent with the proposed electronic structure, based on a comparison to |D/hc| of related biradicals. Finally, the results of variable-temperature EPR spectroscopy are in agreement with ferromagnetic (high-spin) coupling of the two unpaired electrons through the m-phenylene group.
authors.affiliation: Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204.
authors.forename: David A.
authors.initials: DA
authors.lastname: Shultz
authors.forename: Gary T.
authors.initials: GT
authors.lastname: Farmer