A Dinitrogen Dicopper(I) Complex via a Mixed‐Valence Dicopper Hydride. (13th July 2016)

• Record Type: Journal Article
• Authors: Zhang, Shiyu; Fallah, Hengameh; Gardner, Evan J.; Kundu, Subrata; Bertke, Jeffery A.; Cundari, Thomas R.; Warren, Timothy H.
• Is Part Of: Angewandte Chemie. Volume 128:Number 34(2016)
• Page Start: 10081
• Page End: 10085
• Publication Date: 2016-07-13
• Subjects: Distickstoff -- Gemischtvalente Verbindungen -- Hydride -- Kupfer -- Reduktionen; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201603970
• Languages: English
• ISSNs: 0044-8249

Abstract

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 to3 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 ). Although5 thermally decays under N2 to give3, it reduces unsaturated substrates, such as CO and HC≡CPh to HC(O)H and H2 C=CHPh, respectively.