The Synthesis And Investigation Of The Metal Complexes With Tetrazole Acid

The ligand, which has carboxyl groups and nitrogen heterocyclic rings, can coordinate to the metal ions by all kinds of mode. In this dissertation, twenty two new coordination complexes have been synthesized by the solution method. Twenty one of them were studied by IR, Elemental Analysis and single crystal X-ray diffraction methods. The interactions between part of complexes and DNA were studied by UV, CD, fluorescence spectra, viscosity measurement and gel electrophoresis. The solid fluorescence and magnetic properties of part of complexes were measured.There are three chapters in this dissertation:Chapter one: Thirteen new complexes of 1H-tetrazole-5-formic acid were synthesized, and twelve crystal structures of them were determined by X-ray diffraction methods. Variable-temperature magnetic susceptibility of complexes (1) to (4) and (7) to (9) are measured. The complexes (1) to (4) are antiferromagnetic. The magnetic properties of complexes (7) to (9) were complicated because of strong spin-orbit coupling. The interactions between complexes (1), (4), (5), (10), (11) and DNA were studied by UV, CD, fluorescence spectra, viscosity measurement and gel electrophoresis. The results showed that all of the five complexes can interact with DNA. At room temperature, the fluorescence of complex (13) was measured in the solid state. Complex (13) shows the fluorescence emission withλ_em = 519 nm (λ_ex = 338 nm).Chapter two: Six new complexes of 1H-tetrazole-5-acetic acid were synthesized and the crystal structures were determined by X-ray diffraction methods. Variable-temperature magnetic susceptibility of complexes (15) to (19) were performed by using powder samples. The antiferromagnetic interaction among the metal ions was evident from the susceptibility data in complex (15). The metal ions of complexes (16) to (19) were Pr(III), Nd(III), Sm(III) and Gd(III), respectively. The antiferromagnetic interactions are showed in complex (16) and (17) analyzed by the theory of ligand fields approximation. The magnetic property of complex (18) was antiferromagnetic interactions. For complex (19), the antiferromagnetic interactions was showed between two Gd(III) ions.Chapter three: Three new complexes of ethyl tetrazole-5-carboxylate were synthesized and the crystal structures were determined by X-ray diffraction methods. At room temperature, the fluorescence of complexes (20) and (21) are measured in the solid state on the same condition. Complexes (20) and (21) showed the fluorescence emission withλ_em = 378 runλ_ex = 352 nm),λ_em = 396 ran (λ_<sub>ex = 336 run), respectively. The emission observed in complexes (20) and (21) are tentatively assigned to the ligands fluorescence. Variable-temperature magnetic susceptibility of complexes (22) was performed by using powder samples. The interaction between complex (22) and DNA was studied by UV, CD, fluorescence spectra, viscosity measurement and gel electrophoresis. The results showed that the complex can interact with DNA by intercalating mode and can cleavage pBR322 DNA to some extent.