Synthesis of Telechelic Olefin Polymers via Catalyzed Chain Growth on Multinuclear Alkylene Zinc Compounds

Multinuclear alkylene zinc (MAZ) compounds of the type EtZn-(R″-Zn)_<i>n</i>-Et (R″ = ethyl and propyl branched alkylene groups) were synthesized by a simple one-step procedure in nonpolar hydrocarbon solvents from α,ω-dienes (e.g., 1,7-octadiene or 1,9-decadiene) and diethylzinc using a bis­(salicylaldiminato)­Zr­(IV) complex, [(2-methylcyclohexyl)­NCH­(2-O-C₆H₃-3,5-di-<i>tert</i>-butyl)]₂ZrMe₂, as a catalyst. The MAZ serves as a divalent reversible chain-transfer agent for olefin polymerization, resulting in telechelic Zn-metalated polyolefins whose molecular weights are controllable over a wide range. The Zn-terminated telechelics serve as a polymer precursor for further reactions and can be converted into a variety of telechelic functionalized polyolefins in high yield