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

The pendant double bonds in polybutadiene have been hydrosilated by th e reaction of polybutadiene with chlorodimethylsilane in toluene using H2PtCl6 as catalyst. The hydrosilated polybutadiene was further funct ionalised with 2-picolyl, 4-picolyl, 4-dimethylaminophenyl and dipheny lphosphinomethyl Lewis base groups thereby obtaining a series of new p olymeric Lewis bases. All the polymers were found to react with group 13 metal alkyls and the 2- or 4-substituted pyridine functionalised po lymers were also found to react with group 12 metal alkyls to form sol uble polymer adducts. The polymers have been characterised by H-1 nucl ear magnetic resonance (NMR) spectroscopy, C-13 NMR and elemental anal ysis. 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 easil y lost during vacuum drying. The H-1 NMR resonances from the alkyl gro ups on the metal centre shift to a high field upon coordination with N -containing polymeric Lewis bases whilst small downfield shifts are ob served upon coordination of Me3M (M = Ga or ln) with the P-containing polymeric Lewis bases.