Benzyl group abstraction from Ti(CH2Ph)(4) by B(C6F5)(3) and [Ph3C][B(C6F5)(4)] to form Ziegler-Natta and carbocationic alkene polymerization initiators

Reaction,of Ti(CH2Ph)(4) with B(C6F5)(3) results in the formation of [Ti(CH 2Ph)(3)][(eta (6)-PhCH2)B(C6F5)(3)], while reactions with [Ph3C] [B(C6F5)(4 )] give either [Ti(CH2Ph)(3)] [B(C6F5)(4)] or [(CH2Ph)(3)Ti-mu -CH2PhTi(CH2 Ph)(3)][B(C6F5)(4)], depending on the Ti(CH2Ph)(4):[Ph3C] ratio; NMR eviden ce is presented that all of these compounds, including Ti(CH2Ph)(4), exhibi t multihapto Ti-CH2Ph bonding. The Ti(CH2Ph)(4)/B(C6F5)(3) and Ti(CH2Ph)(4) /[Ph3C][B(C6F5)(4)] systems are assessed for their abilities to induce poly merization of ethylene, l-hexene, isobutylene and ethyl vinylether, and the Ti(CH2Ph)(4)/[Ph3C][B(C6F5)(4)] system is found to be able to function as both a Ziegler-Natta catalyst and a carbocationic initiator. (C) 2001 Elsev ier Science B.V. All rights reserved.