Highly trans-1,4-specific polymerization of 1,3-butadiene catalyzed by [2,6-bis{(4 S)- (−)-isopropyl-2-oxazolin-2-yl}pyridine] chromium complex activated with modified methylaluminoxane.

Chromium complexes with N, N, N-tridentate ligands, LCrCl (L = 2,6-bis{(4S)-(−)-isopropyl-2-oxazolin-2-yl}pyridine (), 2,2′:6′,2″-terpyridine (), and 4,4′,4″-tri- tert-butyl-2,2′:6′,2″-terpyridine ()), were prepared. The structures of and were determined by X-ray crystallography. Upon activation with modified methylaluminoxane (MMAO), catalyzed the polymerization of 1,3-butadiene, while and was inactive. The obtained poly(1,3-butadiene) obtained with -MMAO was found to have completely trans-1,4 structure. The -MMAO system also showed catalytic activity for the polymerization of isoprene to give polyisoprene with trans-1,4 (68%) and cis-1,4 (32%) structure. Copyright © 2011 Society of Chemical Industry Upon activation with modified methylaluminoxane (MMAO), the chromium complex CrCl[2,6-bis{(4 S)-(−)-isopro-pyl-2-oxazolin-2-yl}pyridine] () was found to polymerize 1,3-butadiene to produce completely trans-1,4-polymer. [ABSTRACT FROM AUTHOR]