04 mmol al and n bucp 2 zrcl 2 0 1904 mmol 0 077 g was added to the mixture after stirring for 1 h the flask was placed into an oil bath 50 u00b0 c and the solvents were removed under a nitrogen purge to give a free flowing brown powder the catalyst precursor was prepared as in example 1 up to and including the ticl 4 step after removing the flask from the oil bath and allowing it to cool to ambient temperature tma 2 38 mmol was added to the mixture after stirring for 1 h a toluene solution 4 4 ml containing mao 19 04 mmol al and n bucp 2 zrcl 2 0 1904 mmol 0 077 g was added to the mixture after stirring for 1 h the flask was placed into an oil bath 50 u00b0 c and the solvents were removed under a nitrogen purge to give a free flowing brown powder into a schlenk flask were added davison grade 955 silica 2 50 g which was previously calcined at 600 u00b0 c for 4 h and heptane 90 ml the flask was placed into an oil bath kept at 50 u00b0 c dibutylmagnesium 1 80 mmol was added to the stirred silica slurry at 49 u00b0 c and stirring was continued for about 1 h 1 butanol 2 16 mmol butanol mg molar ratio of 1 2 was added at 49 u00b0.