Synthesis, Structural Characterization And Properties Of Selenite And Organotin Compounds Containing Selenium Carboxylic Acid

Organometallics have been vastly explored due to the versatile molecular structures and biochemical activity. Among all the organometallics, the organotin are of great importance. Various organotin derivatives have been researched for their diversity structures and extensive application in pharmaceutical chemistry, asymmetric synthesis and catalysis. The synthesis of highbiological activity of organotin compounds is the hot field of organotin chemistry research. It is well known that selenium is an essential micronutrient in biological system. Organoselenium medicaments which have remakeable effect on the antivirus and anticancer make significant contributions to overcome diseases for humankind. So the antitumor activity may be improved by introducing the selenium into the organotin compounds. In view of the above reasons, we selected and synthesized one benzeneseleninic acidorganotin complexe and two selenocarboxylic acidorganotin complexes and made research of their structure and properties in detail. The main work is as follows:1. 2,4,6-trimethylbenzeneseleninic acid was synthesized and researched via reactions of diorganotin and triorganotin. Finally, we succeeded to make four organotin compounds and characterized by IR, elemental analysis, NMR and X-ray crystallographic. The analysis revealed that:(1) when 2,4,6-trimethylbenzeneseleninic acid reacts with R3SnCl(R = Me, Ph) at 1:1 molar ratio, an infinite 1D polymeric chain were formed. 2,4,6-trimethylbenzeneseleninic acid is the bridging ligand, and the geometry of central tin atom is distorted trigonal bipyramid. When 2,4,6-trimethyl-benzeneseleninic acid reacts with(PhCH2)3SnCl at 1:1 molar ratio, they adopt butterfly cluster, and tin displays hexacoordinated distorted octahedron geometry.(2) when 2,4,6-trimethylbenzeneseleninic acid reacts with Me2SnCl2 in a 2:1 molar ratio, we gained one ladder structures containing Sn2O4Se2 eight-membered ring. The central tin atom defines pentacoordinated distorted trigonal bipyramid geometry and hexacoordinated distorted octahedron geometry.2. 2,4,6-trimethylbenzeneselenoacetic acid and 2,4,6-trimethyl-benzeneacetic acid were synthesized and investigated via reactions of diorganotin and triorganotin. Finally, we succeeded to get seven new organotin compounds and were characterized by NMR, IR, elemental analysis. Six complexes were analyzedby X-ray diffraction. Results indicate that:(1) when 2,4,6-trimethylbenzeneselenoacetic acid reacts with triphenyltin(IV) chloride, the geometry of the novel complex is four-coordinated distorted tetrahedral. When reacts with other trialkyltin chloride, an infinite 1D polymeric chain were formed. Acetic acid as bridging ligands, the geometry of central atom are pentacoordinate distorted trigonal bipyramid.(2) when 2,4,6-trimethylbenzeneselenoacetic acid reacts with diphenyltin(IV) dichloride at 2:1 molar ratio, we acquired drum structure. The geometry of tin atom is hexacoordinated distorted octahedron geometry; when reacts with other dialkyltin dichloride, we acquired ladder structure and the central tin defines penta- coordinate distorted trigonal bipyramid geometry.3. 2-thienylselenoacetic acidwas synthesized and investigated via reactions of diorganotin and triorganotin. Finally, we gained eight organotin compounds and were characterized by NMR, elemental analysis, IR. Seven complexes were also characterized by X-ray crystallographic diffraction analysis. Results indicate that:(1) when 2-thienylselenoacetic acid reacts with triphenyltin(IV) chloride, we gained a centrosymmetric hexanuclear 24-membered macrocycle, the tin defines pentacoordinate distorted trigonal bipyramid geometry; when reacts with other trialkyltin chloride, the structure adopts infinite 1D polymeric chain. The geometry of atom adopts pentacoordinate distorted trigonal bipyramid.(2) when 2-thienylselenoacetic acid reacts with dimethyltin(IV) dichloride at 2:1 molar ratio, we acquired tetranuclear ladder structure; 2-thienylselenoacetic acid reacts with diphenyltin(IV) dichloride, we acquired a hexanuclear drum structure. The geometry of tin defines hexacoordinated distorted octahedron.4. The antitumor activity of some organotin(IV) compounds restrained HeLa and MDA-MB-231 cells were tested by means of MTT testing. The interaction between organotin complexes with bovine serum albumin(BSA) has been studied. The results indicate that the inhibiting effect of these complexes to cancer cells were obvious. We infer that it may be an effective method to improve the antitumor activity by introducing the selenium element into the organotin carboxylates. The fluorescene spectrometry indicated that the intrinsic fluorescene of BSA was quenched by some complexes and the mechanism is static quenching.