A copper(II) chain compound with hydrogenphosphate bridges organized in a double-chain structure. Synthesis, structure and magnetic properties of [Cu(1,10-phenanthroline)(μ-HPO4)(H2O)2]n

A new Cu(II) chain compound, [Cu(1,10-phenanthroline)(μ-HPO4)(H2O)2]n 1 has been synthesized hydrothermally and structurally characterized by elemental analysis, IR, EPR spectrum and single-crystal X-ray diffraction. The Cu(II) ion is tetragonally coordinated with a phen ligand and two aqua ligands in the equatorial plane (Cu–N distance 2.006(2) Å and Cu–O distance 1.969(2) Å) and hydrogenphosphates as axial ligands (Cu–O distance 2.470(2) Å), thereby forming a linear chain. The crystal lattice is formed from antiparallel chains, kept together by relatively strong phosphate–water H-bonds (intra- and intermolecular) with O⋯O contacts of 2.615(3) and 2.672(3) Å and by interpenetrated stacking of the phen ligands with other chains. The magnetic susceptibility measurements (5–300 K) agrees with a weak antiferromagnetic chain interaction between the Cu centers with J value of −5.86 cm−1.