Lewis Acid Supported Nickel Nitrenoids

Abstract

AbstractMetalation of the polynucleating ligand F,tbsLH6 (1,3,5‐C6H9(NC6H3−4‐F−2‐NSiMe2tBu)3) with two equivalents of Zn(N(SiMe3)2)2 affords the dinuclear product (F,tbsLH2)Zn2 (1), which can be further deprotonated to yield (F,tbsL)Zn2Li2(OEt2)4 (2). Transmetalation of 2 with NiCl2(py)2 yields the heterometallic, trinuclear cluster (F,tbsL)Zn2Ni(py) (3). Reduction of 3 with KC8 affords [KC222][(F,tbsL)Zn2Ni] (4) which features a monovalent Ni centre. Addition of 1‐adamantyl azide to 4 generates the bridging μ3‐nitrenoid adduct [K(THF)3][(F,tbsL)Zn2Ni(μ3‐NAd)] (5). EPR spectroscopy reveals that the anionic cluster possesses a doublet ground state (S = ). Cyclic voltammetry of 5 reveals two fully reversible redox events. The dianionic nitrenoid [K2(THF)9][(F,tbsL)Zn2Ni(μ3‐NAd)] (6) was isolated and characterized while the neutral redox isomer was observed to undergo both intra‐ and intermolecular H‐atom abstraction processes. Ni K‐edge XAS studies suggest a divalent oxidation state for the Ni centres in both the monoanionic and dianionic [Zn2Ni] nitrenoid complexes. However, DFT analysis suggests Ni‐borne oxidation for 5.