Synthesis, Structural Characterization And Properties Of Diorganotin(Ⅳ) Complexes Derived From Hydrazone Schiff-base Ligands

Organotin(IV) complexes have received increasing attention owing to their excellentproperties, in particular as potential biological activity。Since biocidal properties oforganotin(IV) compounds are dependent on both the organic group and the ligand attachedto tin, an interesting development is introducing ligands which are themselves bioactive.Acylhydrazones are the most widely used versatile ligands, because they can coordinatemany elements and have some characteristic properties such as thermal stability, rerelevantbiological properties. Up to now many organotin complexes with a variety of hydrazoneshave been studied due to their interesting biological properties,such as antibacterial andantitumor activities，and also because of an interesting variety of structural possibilities. Asan extension of the studies of oganotin(IV) complexes with acylhydrazones, we havesynthesized eighteen new diorganotin(IV) complexes with acylhydrazone and studied theirstructures and biological activities. The main contributions of the thesis are as follows:1. We have successfully prepared five kinds of hydrazone Schiff-base ligands:containing two mono-hydrazones (2-hydroxy-3-methoxy-benzaldehyde-5-bromo-2-hydroxybenzoylhydrazone,2-hydroxy-3-methoxy-benzaldehyde-5-chloro-2-hydroxybenzoylhydrazone)，and three diacylhydrazones (bis(5-chlorosalicylaldehyde)adipicdihydrazone,bis(2-hydroxy-3-methoxybenzylidene)adipicdihydrazide, bis(5-bromo-2-hydroxybenzylidene)succinohydrazide)2. Through the reactions between five kinds of hydrazone Schiff-base ligands andorganotin,18new compounds have been prepared, which have been characterized by useof melting point test, elemental analysis, UV–Vis spectroscopy, Fluorescence spectroscopy,FT-IR, NMR and X-ray diffraction. The results show that: the mono-hydrazonecompounds are mononuclear organotin compounds, in which the tin center is coordinatedwith the enolic tridentate ligand (L) in the ONO chelate mode and exhibitsfive-coordinated or six-coordinated; the dihydrazone compounds are two ligands structureof dinuclear organotin compounds, in which the tin is five-coordinated. Tin atoms andoxygen atoms have a strong role in the compound supramolecular assembly, and for thisforce, molecules assemble into a one-dimensional chain structure or a two-dimensional network structure.3. By means of UV-Vis spectrum and fluorescence spectrum methods, the interactionbetween some compounds and calf thymus DNA and BSA are studied.