Synthesis, Crystal Structures and Magnetic Properties of Two Three-Dimensional Cerium(III) and Erbium(III) Coordination Polymers

Two lanthanide(III) coordination polymers, namely [Ce(pzdc)(1.5)(H2O)](n) (1), [Er(pzdc)(mu(2)-OH)(H2O)](n)center dot nH(2)O (2) (H(2)pzdc = pyrazine-2,5-dicarboxylic acid), have been hydrothermally synthesized and characterized by single crystal X-ray diffraction and magnetic measurements. Polymer 1 crystallizes in triclinic space group P-1, with a = 6.2875(6), b = 6.7396(6), c = 13.3858(14) angstrom, alpha = 82.858(4), beta = 83.118(4), gamma = 63.452(4)degrees, V = 502.16(8) angstrom(3), and Z = 2. Polymer 2 crystallizes in monoclinic space group P2(1)/c, with a = 11.706(4), b = 6.151(2), c = 14.063(5) angstrom, beta = 92.255(3), V = 502.16(8) angstrom(3), and Z = 4. Single-crystal X-ray diffraction studies show that compound 1 possess a 3D framework structure consisted of double chains. Compound 2 features a 3D open framework structure with a dinuclear Er(III) secondary building unit. Magnetic studies for complex 1 show stronger antiferromagnetic coupling between the Ce(III) ions.