Living Polymerization of [o-(Trifluoromethyl)phenyl]acetylene by WOCl4-Based Catalysts Such as WOCl4−n-Bu4Sn−t-BuOH (1:1:1)

A novel WOCl 4 -based ternary catalyst, WOCl 4 − n -Bu 4 Sn− t -BuOH, induced the living polymerization of [ o -(trifluoromethyl)phenyl]acetylene. A catalyst composition of WOCl 4 − n -Bu 4 Sn− t -BuOH = 1:1:1 was suitable, and sterically crowded alcohols such as t -BuOH were favorable as the third catalyst components. The polydispersity ratio of the polymer formed in anisole at 30 °C was as small as 1.04, and the initiation efficiency was no more than about 2%. The living nature of the polymerization was confirmed by the dependence of polymer molecular weight on conversion. Further, two WOCl 4 -based binary systems, WOCl 4 − n -BuLi (1:1−2) and WOCl 4 −EtMgBr (1:1), were also useful as living polymerization catalysts. The polydispersity ratio and the initiation efficiency for the former system (W:Li = 1:1) were 1.08 and 0.9%, respectively, and those for the latter were 1.11 and 5%. These are the first examples of W-based catalysts effective for the living polymerization of substituted acetylenes.