SYNTHESES OF SOLUBLE POLYMERIC LEWIS-BASES AND THEIR ADDUCTS WITH METAL ALKYLS

The pendant double bonds in polybutadiene have been hydrosilated by the reaction of polybutadiene with chlorodimethylsilane in toluene using H2PtCl6 as catalyst. The hydrosilated polybutadiene was further functionalised with 2-picolyl, 4-picolyl, 4-dimethylaminophenyl and diphenylphosphinomethyl Lewis base groups thereby obtaining a series of new polymeric Lewis bases. All the polymers were found to react with group 13 metal alkyls and the 2- or 4-substituted pyridine functionalised polymers were also found to react with group 12 metal alkyls to form soluble polymer adducts. The polymers have been characterised by H-1 nuclear magnetic resonance (NMR) spectroscopy, C-13 NMR and elemental analysis. Integration of H-1 NMR resonances indicates that polymer adducts with M:N or M:P ratios close to 1.0 are obtained when using group 13 metal alkyls, whereas polymer adducts with M:N ratios close to 0.5 are obtained when using group 12 metal alkyls. The metal alkyls are easily lost during vacuum drying. The H-1 NMR resonances from the alkyl groups on the metal centre shift to a high field upon coordination with N-containing polymeric Lewis bases whilst small downfield shifts are observed upon coordination of Me3M (M = Ga or ln) with the P-containing polymeric Lewis bases.