Synthesis, structure, and properties of a tetranuclear copper(II) tridentate Schiff-base complex with a pseudo-double-cubane core

A tetranuclear copper(II) complex, [Cu-4(L)(4)] center dot (NMP), with a tridentate Schiff-base ligand has been synthesized and its crystal structure, spectroscopic properties studied (H2L = salicylidene-2-aminobenzoic alcohol, NMP = N-methylpyrrole). The complex crystallizes in the monoclinic, space group C2/c, with a = 21.461(5), b = 12.231(3), c = 19.898(5) angstrom, beta = 96.402(4)degrees, V = 5190( 2) angstrom(3), Z = 4, and R-1 = 0.0589. The complex is centrosymmetric and the structure can be visualized as a pseudo-double cubane, where both the cubes share a common face and in each cube one of the Cu(II) corners is missing. The four copper atoms are located at the corners of a pseudo-double-cubane core and each copper( II) has square-pyramidal coordination.