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

Abstract

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.

Keywords:

• Triphosphonate anion
• coordination polymer
• magnetic property

Acknowledgement

We thank Department of Education of Liaoning Province (No. L2015299) for financial support.

Notes

1. Two poorly resolved structures were obtained which clearly showed the overall geometries and connectivity would be appropriate. For 1: Monoclinic, P2₁/c, a = 9.0300(8) Å, b = 15.8198(14) Å, c = 9.5601(9) Å, β = 115.312(2)°; For 3: Monoclinic, P2₁/c, a = 9.261(17) Å, b = 16.11(3) Å, c = 9.821 (18) Å, β = 115.57(3)°.