Syntheses, structures and magnetic properties of two new metal complexes based on a pyridyl-diphosphonate ligand

Two new first-raw transition metal diphosphonate complexes, namely, {[Ni3([hpyedpH)2(H2O)4]·(H2O)2}n (1) and [Mn[hpyedpH2](H2O)]n (2), based on a multidentate ligand 1-hydroxy-2-(3-pyridyl)-ethylidene-1,1-diphosphonic acid (hpyedpH4) have been synthesized under hydrothermal reaction and structurally characterized by single-crystal X-ray diffraction, IR spectroscopy and element analyses. The data reveals that complex 1 is a 2D layer structure, whereas the complex 2 possesses a 1D motif. The powder X-ray diffraction (PXRD) patterns for complexes 1 and 2 were collected as well, which match well with the ones calculated from their single-crystal structure data. Magnetic measurements show that complex 1 is a ferrimagnet with Tc = 5.0 K. Magnetic studies of complex 2 indicate antiferromagnetic behavior.