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.