A tetranuclear nickel(II) cluster: bis[μ₃-2,6-bis(methylamino)pyridine(2−)-κ⁴N²:N¹,N⁶:N⁶]bis[μ₃-2,6-bis(methylamino)pyridine(1−)-κ³N¹:N²:N²]dichloridotetranickel(II)

Abstract

The title compound, [Ni4(C7H9N3)2(C7H10N3)2Cl2], was obtained from a reaction in which 2,6-dimethyl­amino­pyridine, in the presence of methyl­lithium used to deprotonate the organic ligand precursor, was added to NiCl2 during an attempt to synthesize a linear trinuclear nickel chain. During this reaction, two equivalents of the amine were fully deprotonated, forming dianions, and the three N atoms coordinate to Ni centers. The other two equivalents of the amine were only partially deprotonated, giving monoanions in which only two N atoms coordinate to Ni centers. In this tetra­nuclear complex, two of the four Ni atoms have square-planar coordination and are bonded to four N donors, while the other two are in a distorted tetra­hedral geometry, with three coordination sites occupied by N donors and the fourth by a Cl atom. The mol­ecule is noncentrosymmetic but the crystal structure is racemic.