A tetra-nuclear nickel(II) complex, [Ni(4)(L)(4)](ClO(4))(4)·C(2)H(3)N·2H(2)O, with an asymmetric Ni(4)O(4) open-cubane-like core.

A tetra-nuclear complex with an open-cubane-like core structure was synthesized from 2-meth-oxy-6-(pyridin-2-yl-hydrazonometh-yl)phenol (HL), namely, cyclo-tetra-kis-(μ-2-meth-oxy-6-{[2-(pyridin-2-yl)hydrazin-1-yl-idene]meth-yl}pheno-lato)tetra-nickel(II) tetra-kis-(perchlorate) aceto-nitrile monosolvate dihydrate, [Ni(4)(C(13)H(12)N(3)O(2))(4)](ClO(4))(4)·C(2)H(3)N·2H(2)O, and characterized using micro-analytical and spectroscopic techniques. The crystal-structure determination reveals the formation of a distorted Ni(4)O(4) cubane-like core architecture encapsulated by four hydrazone Schiff base (HL) mol-ecules. A open-cube tetra-nuclear architecture is created in which nickel(II) ions of the NiN(2)O(3) unit are connected by μ(2)-O anions of the phenolate moiety of HL. In this complex, each Ni centre has a slightly distorted square-pyramidal coordination environment. The supra-molecular architectures are stabilized via the presence of various inter-molecular hydrogen bonds and (ar-yl-aryl, ar-yl-chelate and chelate-chelate) stacking inter-actions.