γ-RADIATION PRODUCED SUPPORTED METAL COMPLEX CATALYSTS II. COBALT CARBONYL HYDROFORMYLATION CATALYSTS SUPPORTED ON POLYPROPYLENE CONTAINING PYRIDINE SIDE CHAINS

Article abstract of DOI:10.1016/S0022-328X(00)83031-4

The optimum conditions necessary to prepare novel polymer supports for use in catalysis by the γ-radiation grafting of 4-vinylpyridine on to polypropylene are shown to be a total dose of 2 Mrad at a dose rate of 300 Krad h^-1 using a monomer to polymer ratio of 40 per cent mol/mol.Addition of 0.1 per cent w/v of p-tert-butylcatechol increases the grafting yield almost two fold.Comparison of the hydroformylation of 1-hexene in the presence of cobalt carbonyl supported on 4-vinylpyridine grafted on to polypropylene shows an increase in specificity, as determined by the ratio of normal/branched heptanal formed, by a factor of about 2.5 over the corresponding homogeneous catalyst.The supported system is of similar activity to the homogeneous system.The greater specificity of the supported catalyst is ascribed to the total environment surrounding the catalytically active site in which both the pyridine sidechain and the polypropylene backbone are believed to play an important role.