title: Electronic Structure of Manganese Complexes of the Redox-Non-innocent Tetrazene Ligand and Evidence for the Metal-Azide/Imido Cycloaddition Intermediate.
abstract: The first synthetic manganese tetrazene complexes are described as a redox pair comprising anionic [Mn(N4 Ad2 )2 ](-) (1) and neutral Mn(N4 Ad2 )2 (2) complexes (N4 Ad2 =[Ad-N-N=N-N-Ad](2-) ). Compound 1 is obtained in two forms as lithium salts, one as a cationic Li2 Mn cluster, and one as a Mn-Li 1D ionic polymer. Compound 1 is electronically described as a Mn(III) center with two [N4 Ad2 ](2-) ligands. The one-electron oxidized 2 is crystalized in two morphologies, one as pure 2 and one as an acetonitrile adduct. Despite similar composition, the behavior of 2 differs in the two morphologies. Compound 2-MeCN is relatively air and temperature stable. Crystalline 2, on the other hand, exhibits a compositional, dynamic disorder wherein the tetrazene metallacycle ring-opens into a metal imide/azide complex detectable by X-ray crystallography and FTIR spectroscopy. Electronic structure of 2 was examined by EPR and XPS spectroscopies and DFT calculations, which indicate 2 is best described as a Mn(III) ion with an anion radical delocalized across the two ligands through spin-polarization effects.
authors.affiliation: Department of Chemistry, Temple University, 1901 N. 13th St., Philadelphia, PA, 19122, USA.
authors.forename: Shivaiah
authors.initials: S
authors.lastname: Vaddypally
authors.affiliation: Department of Chemistry, Temple University, 1901 N. 13th St., Philadelphia, PA, 19122, USA.
authors.forename: Ian G
authors.initials: IG
authors.lastname: McKendry
authors.affiliation: Department of Physics, Naval Postgraduate School, 833 Dyer Rd., Monterey, CA, 93943, USA.
authors.forename: Warren
authors.initials: W
authors.lastname: Tomlinson
authors.affiliation: Department of Physics, Naval Postgraduate School, 833 Dyer Rd., Monterey, CA, 93943, USA. jphooper@nps.edu.
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Hooper
authors.affiliation: Department of Chemistry, Temple University, 1901 N. 13th St., Philadelphia, PA, 19122, USA. mzdilla@temple.edu.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Zdilla
keywords: density functional calculations; energetic materials; non-innocence; tetrazene; valence tautomerism