Shmatkova N. Synthesis, structure and properties of germanium (IV) complex compounds with substituted benzoic and pyridinecarboxylic acids hydrazides arylhydrazones

Object of investigation: germanium (IV) complex compounds with substituted benzoic and pyridinecarboxylic acids hydrazides arylhydrazones. Aim of investigation: to reveal the peculiarities of germanium tetrachloride interaction with substituted benzoic and pyridinecarboxylic acids hydrazides arylhydrazones depending on solvent nature, ligand composition and structure; to state regularities to determine the structure and physical-chemical characteristics of complexes. Methods of investigation: elementary and X-ray phase analysis, conductivity measurements, 1H, 13C NMR, IR and electron spectroscopy, thermogravimetry, mass-spectrometry, X-ray crystal structure analysis. Theoretical and practical results: the systematic study of GeCl4 as Lewis acid complex formation with big series of substituted benzoic and pyridinecarboxylic acids hydrazides benzal-, dimethylaminobenzal- and salicylalhydrazones in organic solvents of different nature (benzene, acetone, ethanol, methanol) has been carried out and their peculiarities have been established. The methods have been devised and for the first time thirty germanium complexes with stated ligands have been synthesized. It has been stated germanium complexes with ligands bidentate coordination to form in benzene and to be unstable in protic solvents. It has been shown the condition of GeCl4 complex formation in protic solvents to be tridentate coordination of salicylalhydrazones type ligands. The structural parameters of octahedral polyhedrons of different composition such as GeCl2O2N2, GeO4N2, GeCl2O3N, GeCl3O2N have been obtained. It has been shown for the first time the formation of germanium supramolecular compounds with hydrazones having donor nitrogen atom out of germanium coordination center. As an example for complexes with pyridinecarboxylic acids salicylalhydrazones the effect of solvent on coordination center composition and ligand form has been displayed. On the grounds of discovered anti-inflammatory activity the prospect of carrying out of further studiesof germanium (IV) complexes with considered hydrazones in this direction has been shown. Degree of inculcation: the developed methods have been introduced into the practice of work of department general chemistry and polymers (the individual part of special course devoted to complex formation and physical-chemical investigation of coordination compounds). Field of application: coordination chemistry.