Synthesis of Cyclic Polyolefin: Ring-Opening Metathesis Polymerization by Binuclear Vanadium Complexes

Main observation and conclusion Ring-opening metathesis polymerization (ROMP) of norbornene by binuclear vanadium alkylidene in-situ formed from dialkyl complexes was investigated. Higher activities were observed by the binuclear system than mononuclear analogues. Especially the cyclic polymers were obtained and demonstrated. It is proposed that cyclic binuclear vanadium alkylidene was afforded due to the intramolecular chain-transfer reaction. The size of polymer ring could be adjusted by the vanadium catalyst structure and polymerization temperature. Similar results were also observed in the ROMP of cyclopentene. [GRAPHICS] .

Automated summary

The binuclear vanadium alkylidene showed higher activity in ROMP of norbornene, leading to the formation of cyclic polymers. The size of the polymer ring could be adjusted by the vanadium catalyst structure and polymerization temperature. Similar results were also observed in the ROMP of cyclopentene.