title: A Dinitrogen Dicopper(I) Complex via a Mixed-Valence Dicopper Hydride.
abstract: Low-temperature reaction of the tris(pyrazolyl)borate copper(II) hydroxide [(iPr2) TpCu]2 (μ-OH)2 with triphenylsilane under a dinitrogen atmosphere gives the bridging dinitrogen complex [(iPr2) TpCu]2 (μ-1,2-N2 ) (3). X-ray crystallography reveals an only slightly activated N2 ligand (N-N: 1.111(6) Å) that bridges between two monovalent (iPr2) TpCu fragments. While DFT studies of mono- and dinuclear copper dinitrogen complexes suggest weak π-backbonding between the d(10) Cu(I) centers and the N2 ligand, they reveal a degree of cooperativity in the dinuclear Cu-N2 -Cu interaction. Addition of MeCN, CNAr(2,6-Me) , or O2 to 3 releases N2 with formation of (iPr2) TpCu(L) (L=NCMe, CNAr(2,6-Me2) ) or [(iPr2) TpCu]2 (μ-η(2) :η(2) -O2 ) (1). Addition of triphenylsilane to [(iPr2) TpCu]2 (μ-OH)2 in pentane allows isolation of a key intermediate [(iPr2) TpCu]2 (μ-H) (5). Although 5 thermally decays under N2 to give 3, it reduces unsaturated substrates, such as CO and HC≡CPh to HC(O)H and H2 C=CHPh, respectively.
authors.affiliation: Department of Chemistry, Georgetown University, Box 571227, Washington, DC, 20057-1227, USA.
authors.forename: Shiyu
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, Center for Advanced Scientific Computing and Modeling (CASCaM), University of North Texas, Denton, TX, 76203, USA.
authors.forename: Hengameh
authors.initials: H
authors.lastname: Fallah
authors.affiliation: Department of Chemistry, Georgetown University, Box 571227, Washington, DC, 20057-1227, USA.
authors.forename: Evan J
authors.identifier: 0000-0003-2945-2951
authors.initials: EJ
authors.lastname: Gardner
authors.affiliation: Department of Chemistry, Georgetown University, Box 571227, Washington, DC, 20057-1227, USA.
authors.forename: Subrata
authors.initials: S
authors.lastname: Kundu
authors.affiliation: Department of Chemistry, Georgetown University, Box 571227, Washington, DC, 20057-1227, USA.
authors.forename: Jeffery A
authors.initials: JA
authors.lastname: Bertke
authors.affiliation: Department of Chemistry, Center for Advanced Scientific Computing and Modeling (CASCaM), University of North Texas, Denton, TX, 76203, USA. t@unt.edu.
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Cundari
authors.affiliation: Department of Chemistry, Georgetown University, Box 571227, Washington, DC, 20057-1227, USA. thw@georgetown.edu.
authors.forename: Timothy H
authors.identifier: 0000-0001-9217-8890
authors.initials: TH
authors.lastname: Warren
keywords: copper; dinitrogen; hydride; mixed-valent compounds; reduction