title: Excited-state mixed-valence distortions in a diisopropyl diphenyl hydrazine cation.
abstract: Excited-state mixed valence (ESMV) occurs in the 1,2-diphenyl-1,2-diisopropyl hydrazine radical cation, a molecule in which the ground state has a symmetrical charge distribution localized primarily on the hydrazine, but the phenyl to hydrazine charge-transfer excited state has two interchangeably equivalent phenyl groups that have different formal oxidation states. Electronic absorption and resonance Raman spectra are presented. The neighboring orbital model is employed to interpret the absorption spectrum and coupling. Resonance Raman spectroscopy is used to determine the excited-state distortions. The frequencies of the enhanced modes from the resonance Raman spectra are used together with the time-dependent theory of spectroscopy to fit the two observed absorption bands that have resolved vibronic structure. The origins of the vibronic structure and relationships with the neighboring orbital model are discussed.
authors.affiliation: Department of Chemistry and Biochemistry, University of California-Los Angeles, CA 90095, USA.
authors.forename: Jenny V
authors.initials: JV
authors.lastname: Lockard
authors.forename: Jeffrey I
authors.initials: JI
authors.lastname: Zink
authors.forename: Yun
authors.initials: Y
authors.lastname: Luo
authors.forename: Michael N
authors.initials: MN
authors.lastname: Weaver
authors.forename: Asgeir E
authors.initials: AE
authors.lastname: Konradsson
authors.forename: Joseph W
authors.initials: JW
authors.lastname: Fowble
authors.forename: Stephen F
authors.initials: SF
authors.lastname: Nelsen
mesh_terms: D002412:Cations / Q000737:chemistry; D005609:Free Radicals / Q000737:chemistry; D006834:Hydrazines / Q000138:chemical synthesis / Q000737:chemistry*; D008956:Models, Chemical; D015394:Molecular Structure; D011789:Quantum Theory; D012680:Sensitivity and Specificity; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D013059:Spectrum Analysis, Raman
chemical_list: D002412:Cations; D005609:Free Radicals; D006834:Hydrazines; C516929:diisopropyl diphenyl hydrazine