Supramolecular structure, IR spectroscopic and magnetic studies of a novel copper (II) complex ([Cu(phen)]2(H2PO4)2HPO4)2(H3PO4)4

A new Cu (II) complex with bidentate o-phenanthroline (phen) ligand, ([Cu(phen)]2(H2PO4)2HPO4)2(H3PO4)4, has been synthesized and characterized by single crystal X-ray diffraction, IR spectroscopy and magnetic data. The crystal structural analysis shows that the title compound contains two phosphate-bridged dimeric units ([Cu(phen)]2(H2PO4)HPO4), which are crystallographically independent. In these units, each copper atom is five coordinated and the geometry around the Cu(II) can be described as slightly distorted square-based pyramidal, with τ parameter varying between 0.001 and 0.04. The crystal structure is stabilized by O–H…O and C–H…O hydrogen bonds between the dimeric units and the phosphoric acid molecules. In addition, the organic ligands are associated by π–π stacking interactions between neighboring non-nitrogen aromatic rings. The infrared spectrum recorded at room temperature was interpreted on the basis of data published in the literature. The magnetic susceptibilities data show a weak intra-dimer ferromagnetic interaction with J = 31.8 K.