Synthesis, characterization and C–H amination reactivity of nickel iminyl complexes

Abstract

Nickel-supported nitrenoids exhibit iminyl character, as determined by multi-edge XAS and TDDFT analysis, demonstrate efficacy for C–H activation and nitrene transfer chemistry.

Terminal Imido Complexes of the Groups 9–11: Electronic Structure and Developments in the Last Decade

“…The tetracoordinated iridium(III) imidyl complex 20 shows an Ir−N bond length of 1.805(2), which also here further elongates upon oxidation to 20 + (1.868(2) Å) due to enhanced nitrene character [46] . Tricoordinated nickel(II) imido complexes such as 3 Ad (1.657(5) Å) [47] and imidyl complex 6 Ad (1.642(7) Å) [36] show Ni−N bonds in the range of 1.64–1.70 Å [32a,b] . The strongly bent nickel(II) imido 4 Ter_Mes with unusual strong closed‐shell character exhibits a significantly longer Ni−N bond (1.732(3) Å) [89] .…”

“…Yet, this compound shares small imidyl character in its ground state as corroborated by a calculated population of 0.3 e − of the π* orbital, which translates into a Löwdin spin density of −0.1 a.u. at the imido nitrogen atom. Nickel Imidyl Complex: Betley and colleagues reported mesityl‐ and adamantyl (Figure 6, right) imido complexes of nickel, supported by a dipyrrinato ligand ( 6 Mes and 6 Ad ; see also Figure 22 below) [36] . Compound 6 Ad can be understood as nickel imidyl complex and features an unpaired electron at the nitrogen ligand.…”

“…The picture is less clear for imidyl complexes. For instance, 6 Ad (M‐N‐R=164.8(17)°) [36] and 7 Mes ((M‐N‐R=168.9(1)°) [37] are at best moderately bent. On the contrary, the linkage in complex 6 Mes , where the metal‐ligand bond is perturbed through spin‐delocalization into the conjugated π‐system of the mesityl substituent, is strongly bent (M‐N‐R=146.5(2)°).…”

“…Nickel Imidyl Complex: Betley and colleagues reported mesityl‐ and adamantyl (Figure 6, right) imido complexes of nickel, supported by a dipyrrinato ligand ( 6 Mes and 6 Ad ; see also Figure 22 below) [36] . Compound 6 Ad can be understood as nickel imidyl complex and features an unpaired electron at the nitrogen ligand.…”

Dipyrrin based metal complexes: reactivity and catalysis

“…Recently, a Ni(I) analogue based on a dpm with a pentafluorophenyl group and adamantyl moieties at the meso and α positions respectively has been shown to also form an iminyl complex upon reaction with 1-adamantylazide, prone to further reaction with toluene to afford an imine. 87…”