SYNTHESIS AND CRYSTAL STRUCTURE OF A THREE-DIMENSIONAL 3d-4f HEIEROMETALLIC COORDINATION POLYMER {[Sm_2Ni(Pdc)_2(SO_4)_2(H_2O)_6] ? H_2O}_n

摘要

A new 3d—4f coordination polymer {[Sm_2Ni(Pdc)_2(SO_4)_2(H_2O)_6] ? H_2O}_n (H_2Pdc = pyridine-3,5-dicarboxylic acid) has been synthesized under hydrothermal conditions and structurally determined by X-ray diffraction method. The X-ray diffraction analysis reveals the compound crystallizes in the triclinic system, space group P1, with a = 10.062(4), b = 10.249(4), с = 12.744(5) ?, α = 93.548(4)°, β = 102.601(4)°, γ = 94.022(3)°, V= 1275.4(8) ?~3, F(000) = 972, M_r = 1077.85, Z= 2, ρ_c = 2.624 g cm~(-3), μ = 5.55 mm~(-1), final R = 0.0299, wR 0.0805 for 4716 independent reflections with R_int) = 0.0204. According to the structure determination the complex is a three-dimensional (3D) network structure in which infinite lanthanide-carboxylate chains are linked by [Ni(SO_4)_2]~(2-) metalloligands to form a mixed-metal coordination network.