Homogeneous Tandem Catalysis of Bis(2-decylthioethyl)amine−Chromium Trimerization Catalyst in Combination with Metallocene Catalysts

Homogeneous tandem catalysis involving a highly selective, aluminoxane-activated bis(2-decylthioethyl)amine·CrCl<INF>3</INF> complex for the synthesis of 1-hexene in tandem with a number of metallocene catalysts is discussed. Analysis by means of DSC, CRYSTAF, HT-GPC, ¹³C NMR, and FTIR suggests that copolymers of 1-hexene and ethylene are produced with significant selectivity toward 1-hexene as comonomer. The selectivity of 1-hexene incorporation by the metallocene catalysts follows the trend in the order [Me<INF>2</INF>Si(2-Me-Ind)<INF>2</INF>]ZrCl<INF>2</INF> > [Me<INF>2</INF>Si(2,3,4,5-Me-Cp)(t-Bu-N)]TiCl<INF>2</INF> > Cp<INF>2</INF>ZrCl<INF>2</INF>. The highly selective nature of the ethylene trimerization catalyst employed in this study means that the industrial application of tandem catalysis is becoming increasingly viable since it approaches conventional 1-hexene LLDPE in terms of polymer microstructure control.