Studies on the Synthesis, Crystal Structures, Spectroscopic Characterization and Magnetic Properties of Complexes of Tetrazole-1-acetic Acid

Studies on the Synthesis, Crystal Structures, Spectroscopic Characterization and Magnetic Properties of Complexes of Tetrazole-1-acetic Acid
　　In this dissertation, fourteen new coordination complexes have been synthesized by the liquid method. They were studied by IR, Elemental Analysis and single crystal X-ray diffraction methods. The magnetic properties of polymers (1) to (4) and the fluorescence spectra data of polymers (7) and (8) are measured.The ligand we used is tetrazole-1-acetic acid (Htza), and it has several coordination modes in this dissertation, as follows:There are three chapters in this dissertation:Chapter one: Five new complexes of Htza with Cu(II) are synthesized by controlling the Ring neodymium magnet pH value of the reaction system or adding the second ligand. They are {[Cu(tza)2(Htza)2]·2H2O}n (1), [Cu(tza)2]n (2), {[Cu2(tza)2(CH3COO)(μ3-OH)(H2O)]·H2O}n (3), [Cu2(tza)3(μ3-OH) 2H2O]n (4), {[Cu(tza)(phen)](ClO4)}n (5). The pH value of the reaction system from (1) to (4) is 2.02.5, 3.0, 3.87, 5.5, respectively. The ligands coordinate with Cu(II) ions via (b) and (c) in complex (1), and the Cu(II) ions are connected to 1-D chain structure. Then, the neighboring chains are assembled to 2-D network structure by hydrogen bonds. In complex (2), the ligands coordinate with Cu(II) ions by (d), and the Cu(II) ions are linked into 2-D network structure. There are twoμ3-OH in one structural cell of complex (3), and four Cu(II) ions are connected by them. Then, the structural cells are linked into 2-D network structure by (d) and (i), and the 2-D network structure is assembled to 3-D meshwork structure via hydrogen bonds.
　　The structure of complex (4) is similar to complex (3). But, there is CH3COO- in complex (3). And the Cu(II) ions of complex (4) are connected to 2-D network structure by (c), (d) and (e).In complex (5), the phen is added in order to study the influence of the second ligand on the complex structure. The spacial resistance is enhanced because the phen coordinates with Cu(II). So the Cu(II) ions of complex (5) are only linked into 1-D z chain structure via (e). Complex (1), (2), (4), (5) belong to monoclinic system, space groups are C2/c, P2(1)/c, P2(1)/n, C2/c, respectively. Complex (3) belongs to Triclinic, space group P-1. Chapter two: Five new polymers are synthesized by reaction of Htza with oxides of Zn, Cd, Pb and perchlorides of Cd, Co in this part. They are [Zn2(tza)3(μ3-OH)(H2O)·2H2O]n (6), [Cd(tza)2]n (7), {[Cd(tza)(2,2?-bipy)(H2O)](ClO4)}n (8), {[Co(tza)(2,2?-bipy)(H2- O)](ClO4)}n (9), [Pb(tza)2]n (10). We study the influence of the second ligand and different metallic ions on the complex structure. In complex (6), the Zn(II) ions are connected to 2-D network structure by (c), (e) and (h). But in complex (7), the ligands link Cd(II) ions into 3-D meshwork structure polymer only via (e). In complex (8), 2,2?-bipy is added and the Cd(II) ions are connected to 2-D network structure by (e). The extension of complex (8) along a axis is limited because the 2,2?-bipy coordinates with Cd(II) ions . But the neighboring planes are assembled into 3-D meshwork supermolecular structure via hydrogen bonds andπ-πstacking. The configuration of Co(II) ions in complex (9) is the same as Cd(II) ions in complex (8). But the corresponding bond length varies a little. In complex (10), the ligands link Pb(II) ions into 1-D chain structure by (f). The Pb(II) ions have two tropism in one chain, and the neighboring Pb(II) ions have Pb-O···Pb weak interaction in adajacent chains.
　　The complex (10) is assembled into 3-D meshwork supermolecular structure by that weak interaction.Complex (6) belongs to Triclinic system, space group P-1. Complex (7) to (10) belong to monoclinic system, and space groups are P2(1)/n、P2(1)/c、P2(1)/c、C2/c, respectively.Chapter three: Four new rare earth polymers are synthesized by reaction of Htza with oxides of rare earth. They are [La(tza)3(H2O)2·2H2O]n (11), [Pr(tza)3(H2O)2·2H2O]n (12), [Nd (tza)3(H2O)2·1.5H2O]n (13), [Sm2(tza)6(H2O)5·H2O]n (14). The configuration of http://www.chinamagnets.biz/ metal ions are the same in complex (11) and (12), and the metal ions are connected to 1-D chain structure via (c) and (g). Then, the chains are assembled into 3-D meshwork supermolecular structure by hydrogen bonds. In complex (13), the configuration of Nd(III) ions is the same as complex (11) and (12), but the arrangement of ligands is changed. There are two kinds of Sm(III) ions in complex (14). The configuration of Sm(III)1 ions is the same as Nd(III) ions in complex (13), but the Sm(III)2 ions are eight-coordinated and they are dinuclear cells. Adjacent dinuclear cells are linked into 2-D network structure by intermolecular hydrogen bonds. Then, the chains of Sm(III)1 and the 2-D network structure of Sm(III)2 are assembled into 3-D meshwork supermolecular structure.Complex (11) and (12) belong to monoclinic system, space groups are all P2(1)/c; Complex (13) and (14) belong to Triclinic system, space groups are all P-1.Variable-temperature magnetic susceptibility of complexes (1) to (4) were performed in the 2320 K region by using powder samples. The antiferromagnetic interaction among the metal ions are evident from the susceptibility data in complex (1) and ferromagnetic interaction in complex (2); And the pure antiferromagnetic interactions are showed in complex (3) and (4).At room temperature, the fluorescence of complex (7) and (8) are measured in the solid state on the same condition. There is no fluorescence emission in complex (7). While complex (8) shows the fluorescence emission withλem = 445 nm (λex = 397 nm). The emission observed in complex (8) is tentatively assigned to the ligands fluorescence(LLCT).