Oxidative assembly of octahedral nickel(II)-tris(3,5-dimethylpyrazol-1-yl)methane (Tpm∗) complexes by reaction of Ni(COD)2 (COD = 1,5-cyclooctadiene) with putative oxene and nitrene precursors

Abstract Reactions of [Ni 0 (COD) 2 ] (COD = 1,5-cyclooctadiene) with meta -chloroperoxybenzoic acid, phenyl- N -tosylimidoiodinane or 2-( tert -butylsulfonyl)iodosylbenzene were performed in THF solution in the presence of one equivalent of tris(3,5-dimethylpyrazol-1-yl)methane (Tpm ∗ ), yielding the product complexes [Tpm ∗ Ni II (OH 2 )(3-ClC 6 H 4 CO 2 ) 2 ] ( 2 ), [(Tpm ∗ ) 2 Ni II ][Ni II (NHTs) 4 ] ( 3 ), and [Tpm ∗ Ni II (OH) 2 (OH 2 )] ( 4 ), respectively. Products 2 – 4 arise from oxidation of solvated [Ni 0 (COD) 2 ], with subsequent ligation of Tpm ∗ and substrate fragments leading to assembly of disparate octahedral nickel(II) centers. For comparative purposes, the previously reported complex [(Tpm ∗ )Ni II (OH 2 )Cl 2 ] ( 1 ) was also obtained from Tpm ∗ and NiCl 2 . All complexes were characterized spectroscopically, and complexes 1 – 3 were also structurally characterized by X-ray crystallography.