Synthesis, structures, and properties of a series of similar structural coordination polymers with triphosphonate anions as ligands

The hydrothermal reactions of metal precursors with aminotri(methylenephosphonic acid) yielded a series of similar structural coordination polymers of general formula {M[HN(CH2PO3H)(3)](H2O)(3)}(n) [M = Mg(II) (1), Mn(II) (2), Co(II) (3), Zn(II) (4) and Cd(II) (5)]. Compounds 1-5 were characterized by X-ray single crystal diffraction, elemental analyses, and thermogravimetric analyses. Compounds 1-5 all reveal the wave-like 1D chain structures and the structures are constructed by two types of eight-membered, square-like rings linked alternatively via the phosphonate oxygen atoms, generating double-channel systems. The magnetic studies of 2 and 3 reveal that antiferromagnetic interactions are mediated between the metal ions.