|
Ten transition metal compounds （1 10） were synthesized by the self-assemble method, using maleate ligand （male） as the first ligand and the bidentate chelating ligands 1, 10-phenanthroline （phen） or 2, 2’-bipyridine （bipy） as the second ligand. These complexes are [Ni（bipy）（H2O）3（male）] · H2O （1）;[Cd（phen）（H2O）2（male）2/2]n 2nH2O （2）;[Mn（phenXH2O）2（male）2/2]n · 2nH2O （3）;[Cu（bipy）（H2O）（male）] · 2H2O （4）;{[Cu（phen）]2（male）2} · 4H2O · CH3OH （5）;[Cu（bipy）（male）2/2]n · 2nH2O （6）;[Zn（phen）（H2O）（male）2/2]n （7）;[Cd（bipy）（H2O）（male）-（2/2）]n·2nH2O （8）;[Cd（phen）-（H2O）（male）2/2]n·2nH2O （9） and [Cd（phen）（male）2/2]n （10）. All the compounds were characterized by the IR and element analyses. The crystal structures of these compounds were determined by X-ray single crystal diffraction method. Futhermore, the thermal stability was analysized by the TG and DSC for all the complexes, and the fluorescent properties were studied for compounds 7 10. The main results are as following:1. Compounds 1, 4, 6, 8 10 belong to monoclinic crystal system and P2（l）/c spacegroup, the cell parameters, 1: a = 9.4941（19） A, b = 7.6031（15） A, c = 23.408（5） A,β = 97.73（3）°, Z = 4;4: a = 8.9793（18） A, b = 22.487（5） A, c = 7.7187（15） A,β = 95.62（3）°, Z = 4;6: a = 12.4361（9） A, b = 17.7345（17） A, c = 8.5620（6） A,β = 98.3730（2）°, Z = 4;8: a = 8.0855（6） A, b = 8.8093（6） A, c = 23.2620（16） A,β = 91.1590（10）°, Z = 4;9: a = 8.2433（6） A, b = 8.7052（6） A, c = 24.5619（18） A,β = 94.0380（10）°, Z = 4;10: a = 11.1519（7） A, b = 10.3844（7） A, c = 12.8994（8）A, β = 117.060（10）°, Z = 4. Compounds 5 and 7 also are monoclinic crystalsystem, but the space groups are C2/c and P2（1）/m, respectively. The cellparameters, 5: a = 18.2216（17） A, b = 12.4609（12） A, c = 14.5122（14） A, β =103.669（2）°, Z = 4;7: a = 9.9906（8） A, b = 7.2954（6） A, c = 10.2946（9） A, β=91.8930（10）°, Z = 2;compounds 2 and 3 belong to triclinic crystal system and P-1space group, the cell parameters, 2: a = 8.1423（8） A, b = 8.1622（8） A, c =13.8095（13） A, a = 80.4520（10）°, β = 87.7160（10）°, γ = 77.673（2）°, Z = 2;3: a = 8.2157（7） A, b = 8.0637（7） A, c = 12.990（12） A, a = 81.543（10）°, β=86.776（10）°, Y = 78.0390（10）°, Z = 2.2. The central metal atoms in compounds 1,2, 3 and 7, namely, Ni（II）, Cd（II）, Mn（II） and Zn（II）, respectively, all have a distorted octahedronal coordination mode;the Cu（II） within compounds 4 6 all have a distorted square pyramidal surrounding, and Cd（II） of 8-10 all are seven coordinated, whereas their structure are different and both the fromers 8 and 9 are distorted pentagon bipyramid, but 10 is octahedron with a cap. The coordination modes of maleate ligand within these compounds are diverse, including, monodentate, bridging bisdentate, chelating bidentate, chelating and bridging trisdentate, and chelating and bridging tetradentate as well. Due to the multi-coordination mode of maleate ligand, the structures of these compounds are different and various. The compounds 1, 4 and 5 have 0D structure, and 2, 3, 6 9 show ID infinite chain structure, but 10 is 2D infinite layer network. All compounds hold 3D networks through the self-assemble method depending on non-covalent bond interactions.3. The results of thermal analyses for the compounds show that all compounds are decomposed at high temperature. Generally speaking, CO or CChwere released before the solvent, due to the hydrogen bond interactions or hydrolyzation of compounds. The decomposition temperatures of the coordination ligands phen and bipy range from 200 to 500 °C, varied with the central metal atoms. The Cu（II） and Zn（II） compounds （4 7） are more unstable than the other compounds, which begin to decompose at the melting point and the others’s decomposition temperatures are relatively higher.4. The compounds 7 10 at the solid state show fluorescent emission bands around 390 nm, 393 nm, 393 nm and 407 nm, resectively, under 357 nm light excitation. The emission can be assigned to the n *— n transition of the phen or bipy ligand. The shapes of emission spectra are similary for the composition of compounds with the same or similary ligands.
|