Solvothermal synthesis, crystal structure, magnetic and luminescent properties of (H3O)6.[Co4(H2O)4(HPMIDA)2(PMIDA)2)].2H2O

A cobalt phosphonate (H3O)6.[Co4(H2O)4(HPMIDA)2(PMIDA)2)].2H2O, 1, has been synthesized from a mild solvothermal reaction of Co(II) ion with N-(phosphonomethyl)iminodiacetic acid (H4PMIDA). Compound 1 crystallizes in the triclinic space group P1-bar with cell parameters of a=9.0682(18)A, b=10.744(2)A, c=12.731(3)A, α=93.06(3)o, β=99.66(3)o, γ=90.34(3)oV=1221.0(4)A3 and Z=1. Compound 1 shows a novel tetra-nuclear molecular structure. In the crystal lattice, molecules of 1 hydrogen bond to each other to form two-dimensional (2D) layers, which are further linked together by the co-crystallized H2O molecules and H3O+ counter ions through hydrogen bonding to form the 3D supramolecular network. Thermogravimetric analysis, IR spectrum, magnetic susceptibility and luminescent spectra are given