Electronic Structure of Manganese Complexes of the Redox‐Non‐innocent Tetrazene Ligand and Evidence for the Metal‐Azide/Imido Cycloaddition Intermediate |
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| Authors: | Dr Shivaiah Vaddypally Ian G McKendry Warren Tomlinson Dr Joseph P Hooper Dr Michael J Zdilla |
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| Institution: | 1. Department of Chemistry, Temple University, Philadelphia, PA, USA;2. Department of Physics, Naval Postgraduate School, Monterey, CA, USA |
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| Abstract: | The first synthetic manganese tetrazene complexes are described as a redox pair comprising anionic Mn(N4Ad2)2]? ( 1 ) and neutral Mn(N4Ad2)2 ( 2 ) complexes (N4Ad2=Ad‐N?N=N?N‐Ad]2?). Compound 1 is obtained in two forms as lithium salts, one as a cationic Li2Mn cluster, and one as a Mn–Li 1D ionic polymer. Compound 1 is electronically described as a MnIII center with two N4Ad2]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 MnIII ion with an anion radical delocalized across the two ligands through spin‐polarization effects. |
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| Keywords: | density functional calculations energetic materials non-innocence tetrazene valence tautomerism |
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