Synthesis, Structures, And Properties Of Metal Complexes Containing Substituted Dihydrazone Ligands

In this thesis,2,6-pyridine-dicarboxylic acid was as the raw material. Dimethyl pyridine-2,6-dicarboxylate was obtained by esterification reaction. pyridine-2,6dicarbohydrazide was synthesized via condensation reaction between the dimethyl pyridine-2,6-dicarboxylate with hydrazine hydrate. N,N-bis(3-hydroxybenzylidene)pyridine-2,6-dicarbohydrazide,N,N-bis(2-hyd roxybenzylidene) pyridine-2,6-dicarbohydrazide and N,N-bis(4-hydroxybenz ylidene) pyridine-2,6-dicarbohydrazide were synthesized by the condensation reaction of pyridine-2,6dicarbohydrazide with3-hydroxybenzaldehyde, salicyladehyde and4-hydroxybenzaldehyde, respectively. Finally N,N-bis(3-hydroxybenzylidene)pyridine-2,6-dicarbohydrazide Cu, Co, Ni complexes were synthesized. The structures of the synthesized compounds were confir-med by1H-NMR spectroscopy, UV-vis,IR,elemental analysis, melting point determination and X-ray crystallography. N,N-bis(3-hydroxybenzyl-idene)pyridine-2,6-dicarbohydrazide identified the role of copper ions by UV titration. The main content of this paper and the results were as follows:1. In this paper,2,6-pyridine-dicarboxylic acid was as the raw material, according to the Synthesis of literature, dimethyl pyridine-2,6-dicarboxylate was obtained. The structure of the synthesized compound was characterized by elemental analysis and melting point determination. N,N-bis(3-hydroxybenzylidene)pyridine-2,6-dicarbohydrazide,N,N-bis(2-hyd roxybenzylidene) pyridine-2,6-dicarbohydrazide and N,N-bis(4-hydroxybenz ylidene) pyridine-2,6-dicarbohydrazide were synthesized by the condensation reaction of pyridine-2,6dicarbohydrazide with3-hydroxybenzaldehyde, salicyladehyde and4-hydroxybenzaldehyde, respectively. Finally N,N-bis(3-hydroxybenzylidene)pyridine-2,6-dicarbohydrazide Cu, Co, Ni complexes were synthesized. The synthesized Co complexes was single crystal, Complexes of Co contained three cobalt ions in the single crystal structure, which having two Co3+and a Co2+ 2. Using UV-visible spectroscopy, hydrazone ligands obtained was titrat ed with metal ion, It was shown that N,N-bis(3-hydroxybenzylidene)pyridine-2,6-dicarbohydrazide combined well with Cu2+, Co2+and Ni2+ions. The hyd razone ligands could identify the role of Cu2+ions from the titration curve.