Syntheses and Structures of Three Novel 1-D Lanthanide-isonicotinate Coordination Polymers

Three novel lanthanide-IN coordination polymers [Ln(IN)3(H2O)2]n (Ln = Sm 1, Dy 2, Eu 3; IN = isonicotinate) have been hydrothermally synthesized and characterized by FT-IR spectra, elemental analysis and TG analysis. Single-crystal X-ray diffraction shows that 1, 2 and 3 are isostructural. Crystal data for 1: monoclinic, space group C2/c, a = 15.8384(14), b = 14.2662 (12), c = 9.5073(7) , β = 97.705(4)°, V = 2128.8(3) 3, Z = 4, Dc = 1.724 g/cm3, F(000) = 1084, μ = 2.806 mm-1 and R = 0.0226; Crystal data for 2: monoclinic, space group C2/c, a = 15.7890(3), b = 14.1356(6), c = 9.5152(3) , β = 97.899(2)°, V = 2103.52(12) 3, Z = 4, Dc = 1.784 g/cm3, F(000) = 1100, μ = 3.601 mm-1 and R = 0.0406; Crystal data for 3: monoclinic, space group C2/c, a = 15.802(5), b = 14.242(4), c = 9.513(3) , β = 97.695(5)°, V = 2121.8(10) 3, Z = 4, Dc = 1.735 g/cm3, F(000) = 1088, μ = 3.004 mm-1 and R = 0.0273. In the three compounds, the Ln(III) centers are eight-coordinated with antiprismatic geometry. The Ln(IN)3(H2O)2 unit connects mutually to form a one-dimensional double zigzag chain via isonicotinate oxygen bridging. The infinite chains are further linked by inter-chain hydrogen-bonding to form a three-dimensional supramolecular network.