Hydrothermal synthesis and thermal analyses of an infinite three-dimensional coordination polymer based on formic acid: [Zn(HCOO) ₂(H₂O)₂]_∞

The coordination polymer [Zn(HCOO)₂(H₂O) ₂]_∞ has been synthesized using hydrothermal method and characterized by X-ray single crystal diffraction, elemental analysis, FTIR spectroscopy and TG-DTG analyses. The coordination polymer crystallizes in monoclinic, P2₁/c space group with crystal parameters of a=0.8688(1) nm, b= 0.7143(6) nm, c=0.9305(2) nm, β=97.61(5)°, V=0.5724(2) nm ³, Z=4, μ(Mo Kα)=42.50 cm^-1. The polymer features with two kinds of zinc centers: one is hexa-coordinated by four water ligands, two oxygen atoms of two formates and the other is coordinated by six oxygen atoms of six formates. By the formates as space linkers, three-dimensional frameworks were formed. Based on thermal analyses, thermal decomposition mechanisms were predicted that at the first step the polymer lost two coordination water molecules and at the second step lost two formates companied by the formation of some kinds of materials.