Amino-functionalized zirconocene (C5H4CH(Me)NMe2)2ZrCl2, a catalyst for the dehydropolymerization of PhSiH3: Probing of peripheral substituent effects on catalyst dehydropolymerization activity

The amino-functionalized metallocene (C5H4CH(Me)NMe2)2ZrCl2, [(CpN)2ZrCl2] was synthesized by salt metathesis of ZrCl4 and 2 equiv. of C5H4CH(Me)NMe2Li. The metallocene was obtained in good yield as a mixture of rac and meso diastereomers as established by NMR spectroscopy. The addition of 2 equiv. of n-BuLi to the metallocene (CpN)2ZrCl2 produced a co-catalyst system which was active, at a 1.0 mol% loading, in the dehydropolymerization of PhSiH3 to poly(phenylsilane), PPSi. The PPSi was obtained as a 9:1 linear–cyclic mixture (Mw=3850, Mn=2300) as established by GPC analysis; 29Si{1H} NMR spectroscopy revealed an atactic polymer microstructure.