Crystal structure of l-4-oxidobenzoato-kappa O-2(1) : O-4 bis[bis(1,10-phenanthroline-kappa(2) N, N ') copper(II)] bis(4-hydroxybenzoate) 7.5-hydrate

The title hydrated complex, [Cu-2(C7H4O3)(C12H8N2)(4)](C7H5O3)(2) center dot 7.5H(2)O, is composed of dinuclear Cu II complex cations, noncoordinating 4-hydroxybenzoate anions and water molecules of crystallization. In the dinuclear complex cation, the Cu II ions are bridged by a 4-oxidobenzoate ligand and thus each metal ion is five-coordinated by two chelating 1,10-phenanthroline (phen) molecules and one anionic O atom in a distorted trigonal-bipyramid geometry. In the crystal, aromatic pi-pi stacking occurs between phen rings of neighbouring dinuclear Cu II complex cations, forming two-dimensional supramolecular systems parallel to (100).