HYDROLYSIS OF MONOBUTYLTIN TRIALKOXIDES - SYNTHESIS AND CHARACTERIZATIONS OF ((BUSN)(12)O-14(OH)(6))(OH)(2)

Hydrolysis-condensation of butyltin triisopropoxide and butyltin tri-tert-amyloxide with more than three water molecules per tin atom yields only the cagelike oxo-hydroxo butyltin cluster, {(BuSn)(12)O-14(OH)(6)}(OH)(2). Its molecular structure has been resolved by X-ray diffraction in the crystalline compound {(BuSn)(12)(mu(3)-O)(14)(mu(2)OH)(6)}(OH)(2)(HOPri)(4). This cluster has also been characterized in solution by Sn-119, H-1, and C-13 NMR spectroscopies. The Sn-119-Sn-119/117 two bond coupling satellites oberved in the solution Sn-119 NMR spectrum have allowed measurement of four scalar coupling constants that can be correlated to the Sn-O-Sn framework. Two dimensional NMR experiments have unambiguously allowed assignment of all the H-1 and C-13 resonances of the cluster and showed that the coordination of tin is felt, at least, up to the third carbon of the butyl chains. The Sn-119 MAS NMR technique was also used to characterize solid compounds. The shielding tensorial properties are reported and discussed in relation to the oxo-hydroxo butyltin cluster structure.