| In recent years, the syntheses crystal structures and properties of polynuclear complexes become one of the subjects of intensive research in the fields of coordination chemistry, due to their important function in the fields not only life science but also in molecule magnetic materials. In this dissertation, the studies on the heterometallic lanthanide-transition metal compounds and the complexes of pyridine-2,6-dicarboxylic acid have been reviewed in detail. More than ten new polynuclear complexes have been synthesized by the solution reaction,hydrothermal reation and the diffusion between two kinds of reactant solutions. Six of them were studied by IR,Elemental Analysis and single crystal X-ray diffraction methods. The variable-temperature magnetic susceptibility data of several complexes are measured. Two novel 3-D Lanthanide-transition metal polymers with well-defined pores [{[Ln2Cu6(4,4＇-bpy)6(dipic)6]·(H2O)8}n], Ln=Gd (1),Er(2),H2dipic= pyridine-2,6-dicarboxylic acid, 4,4＇-bpy=4,4＇-Bipyridine. Have been synthesized by hydrothermal reaction at 150℃ for 4 days. The complex 1 crystallizes in monoclinic space group P2/c with cell parameters a = 23.646(3) ?, b = 10.5214(14) ?, c = 21.663(3) ?, ?= 90°, ?= 105.269(2)°, ? = 90°, V=5199.1(12) ?3, Z=4. Complex 2 crystallizes in monoclinic space group P2/c with cell parameters a = 23.646(3) ?, b = 10.5377(16) ?, c = 21.639(3) ?, ?= 90°, ?= 105.443(3)°, ? = 90°, V=5197.1(14) ?3, Z=4. Complex 1 and 2 are isostructural .in the title complexes, Ln(III) ions and Cu(I) ions are connected by the heterometallic bridging ligand of dipic2- , it is extended into an infinite 3-D network structure by the formation of bringing of Cu-4,4＇-bpy-Cu. There are three types pores in the compound 1 and 2.The complex of the formulation [NdCo(NTA)2(H2O)11/3(CH3OH)1/3] ·(CH3OH)2/3·10/3H2O (3) was obtained by the diffusion between two kinds of reactions. it crystallizes in triclinic space group Pī with cell parameters a = 9.636(2) ?, b = 10.449(2) ?, c = 13.393(2) ?, ?= 107.04°, ?= 98.25(2)°, ? = 103.98°, V=1217.2(4) ?3, Z=2. The crystal structure comprises infinite chains.The complex [Nd2Co3(edta)3(H2O)11·12H2O] (4) crystallizes in monoclinic space group C2 with cell parameters a = 15.925(3) ?, b = 14.655(2) ?, c = 14.741(2) ?, ?= 90°, ?= 116.407(2)°, ? = 90°, V=3081.3(8) ?3, Z=2. Each Nd3+ is connected to three Co2+ through three carboxylate bridges, while each Co2+ has two Nd3+neighbors. In this way, a twelve member macrocycle involing six Nd ions and six Co ions is produced. The cycles are connected each other to form a two-dimension network sheet. These sheets are further linked into a three-dimensional network by the water molecules between the layers through rich hydrogen bonds.Two new complexes of the formula [Cu4(dipic)4(4,4(-bpy)2(H2O)2]·6H2O (5) and [Cu2(dipic)2(Hinic)2(H2O)2]·3H2O(6)have been synthesized by hydrothermal reaction at different temperature and time. The complex 5 crystallizes in triclinic space group Pī with cell parameters a = 7.2375(10) ?, b = 10.6403(18) ?, c = 17.776(3) ?, ?= 79.521(4)°, ?= 83.641(4)°, ? = 71.831(4)°, V=1277.0(4) ?3, Z=2. Cu(II) ions are connected by bridged oxygen atoms from the carboxylate group of H2dipic and 4,4＇-bpy forming one-dimensional "ladder"arrays, then 2-D network by hydrogen bonding. The complex 6 crystallizes in triclinic space group Pī with cell parameters a = 0.72375(10), b = 1.22205(17), c = 1.7078 (2) nm; ( = 90.463(2) °, ( = 91.830(2) °, ( = 93.563(2) °; V = 1.5067 (4) nm3, Z = 2. the complex have 3-D network by hydrogen bonding. Variable-temperature magnetic susceptibility measurements were performed on powder samples of compex (1), (2) and (5)in the 3.99-300K temperature range. The ferromagnetic interactions among the metal ions are evident from the susceptibility data.
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