Synthesis, Characterization, and Heterobimetallic Cooperation in a Titanium–Chromium Catalyst for Highly Branched Polyethylenes

A heterobimetallic catalyst, {Ti--Cr}, consisting of a constrained-geometry titanium olefin polymerization center (CGCEtTi) covalently linked to a chromium bis­(thioether)­amine ethylene trimerization center (SNSCr) was synthesized and fully characterized. In ethylene homopolymerizations it affords linear low-density polyethylene with molecular weights as high as 460 kg·mol–1 and exclusively n-butyl branches in conversion-insensitive densities of ∼18 branches/1000 carbon atoms, which are ∼17 and ∼3 times (conversion-dependent), respectively, those achieved by tandem mononuclear CGCEtTi and SNSCr catalysts under identical reaction conditions.