Synthesis and crystal structure of a new chiral α-amino-oxime nickel(II) complex

A dinuclear nickel complex with (S)-limonene based amino-oxime ligand has been isolated and its crystal structure determined. The resolved structure of dichloridobis-{(2S,5R)-2-methyl-5-(prop-1-en-2-yl)-2-[(pyridin-2-yl)methyl-amino]-cyclo-hexan-1-one oxime}dinickel(II), [Ni₂Cl₂(C₁₆H₂₃ClN₃O)₂], at 100 K has monoclinic (P2₁) symmetry. The two Ni^II ions in the dinuclear complex are each coordinated in a distorted octa-hedral environment by three nitro-gen atoms, a terminal chloride and two μ bridging chlorides. Each oxime ligand is coordinated to nickel(II) by the three nitro-gen atoms, leading to two five-membered chelate rings, each displaying an envelope conformation. In the crystal, numerous inter-molecular and intra-molecular hydrogen bonds lead to the formation of a three-dimensional network structure.