|Budget Amount *help
¥7,800,000 (Direct Cost : ¥7,800,000)
Fiscal Year 1996 : ¥2,500,000 (Direct Cost : ¥2,500,000)
Fiscal Year 1995 : ¥5,300,000 (Direct Cost : ¥5,300,000)
Results of speciation, equilibrium, and structural characterization of organotin (IV) compounds in aqueous solution are as follows :
1. Hydrolysis and complexation of organotin (IV) compounds in aqueous solution
(1) Equilibrium constants for hydrolysis of dimethyltin (IV), trimethyltin (IV), and triethyltin (IV) ions were determined by potentiometry. Hydroxo-bridged polymers exist. The relation between their structures and polymerization reactions has been clarified.
(2) Equilibrium constans for complexation of dimethyltin (IV) and trimethyltin (IV) with aminopolycarboxylates (EDTA,NTA,EDDA,MIDA,PDA) were determined. Electron donicity of the ligands is important for the structure which affects the chelate formation.
2. Determination of structure of organotin (IV) conpounds
(1) Crystal structures of complexes of dimethyltin (IV) with five aminopolycarboxylates were determined by X-ray analysis. It has been demonstrated that the tin atom is versatile for 3-, 4-, 5-, 6-, and 7-coordinate and that the configuration of the tin is affected by donation of the ligands.
(2) By the EXAFS method, were determined the structures around the central tin atoms for several organotin (IV) compounds in an scidic aqueous solution.
3. Decomposition of organotin (IV) compounds by laser
Decomposed products of methyltin (IV) and tetraphenyltin (IV) by laser were analyzed by ^1H-NMR and the dynamic behavior of triphenyltin (IV) radical produced was observed as a function of water concentration.