Supramolecular bidentate amine derivatives of copper(ii) organophosphonates

Abstract

Four novel complexes of copper(II) with organophosphonic acids and bidentate amines: [CuD_n((OH)O₂PR)][(OH)O₂PR)]·(H₂O)_x, where D = 1,10-phenanthroline (C₁₂H₈N₂ or phen) or 2,2′-bipyridyl (C₁₀H₈N₂ or 2,2′-bipy), n = 1 or 2, R = C₆H₅ or CH₂C₆H₅, and x = 0, 1, 4 or 7, have been synthesised by hydrothermal reactions at 160 °C. A combination of structural studies and various analytical techniques indicate that for species where D = phen and R = C₆H₅ (1), and where D = phen and R = CH₂C₆H₅ (2), the compounds are crystalline ionic materials possessing triclinic and monoclinic structures, respectively. The crystal structures of (1) and (2) are supramolecular and contain ribbons of [Cu(phen)₂((OH)O₂PR)]⁺ cations, interleaved between H-bonded sheets of organophosphonate anions and water molecules. The data compiled for the 2,2′-bipy derivatives (3–4) are somewhat different from the phen species, indicating there is only one amine ligand for each copper atom. Powder XRD, FTIR, TGA, UV-Vis, and XPS data consistent with the formulations are presented.