title: Redox-Initiated Reactivity of Dinuclear β-Diketiminatoniobium Imido Complexes.
abstract: High-valent dichloride and dimethylniobium complexes 1 and 2 bearing tert-butylimido and N,N'-bis(2,4,6-trimethylphenyl)-β-diketiminate (BDIAr) ligands were prepared. The dimethyl complex reacted with dihydrogen to release methane and generate the hydride-bridged diniobium(IV) complex 3 in high yield. One-electron oxidation of 3 with silver salts resulted in the release of dihydrogen and conversion to a mixed-valent NbIII-NbIVcomplex, 4, that displayed a frozen-solution X-band electron paramagnetic resonance signal consistent with a slight dissymmetry between the two Nb centers. Spectroscopic and computational analysis supported the presence of Nb-Nb σ-bonding interactions in both 3 and 4. Finally, one-electron reduction of 4 resulted in conversion to the highly dissymmetric NbV-NbVdimer 5 that formed from the reductive C-N bond cleavage of one of the BDIArsupporting ligands.
authors.affiliation: Department of Chemistry, University of California , Berkeley, California 94720, United States.
authors.forename: Benjamin M
authors.identifier: http://orcid.org/0000-0003-4915-6084
authors.initials: BM
authors.lastname: Kriegel
authors.affiliation: Department of Chemistry, University of California , Berkeley, California 94720, United States.|Ecole Polytechnique Fédérale de Lausanne, Institut des Sciences et Ingénierie Chimiques , CH-1015 Lausanne, Switzerland.
authors.forename: Lara C E
authors.initials: LC
authors.lastname: Naested
authors.affiliation: LCM, CNRS, Ecole Polytechnique, Université Paris-Saclay , Route de Saclay, 91128 Palaiseau Cedex, France.
authors.forename: Grégory
authors.initials: G
authors.lastname: Nocton
authors.affiliation: Department of Chemistry and Chemical Biology and The Baruch '60 Center for Biochemical Solar Energy Research, Rensselaer Polytechnic Institute , Troy, New York 12180, United States.
authors.forename: K V
authors.initials: KV
authors.lastname: Lakshmi
authors.affiliation: Department of Chemistry, University of California , Berkeley, California 94720, United States.
authors.forename: Trevor D
authors.identifier: http://orcid.org/0000-0003-3568-7861
authors.initials: TD
authors.lastname: Lohrey
authors.affiliation: Department of Chemistry, University of California , Berkeley, California 94720, United States.
authors.forename: Robert G
authors.initials: RG
authors.lastname: Bergman
authors.affiliation: Department of Chemistry, University of California , Berkeley, California 94720, United States.
authors.forename: John
authors.identifier: http://orcid.org/0000-0001-9671-227X
authors.initials: J
authors.lastname: Arnold