Synthesis, characterization, and polymerization activity of (pentamethylcyclopentadienyl)titanatranes containing {(O-2,4-Me 2C 6H 2-6-CH 2) nN(CH 2CH 2O) 3−n} 3− ( n = 0–2) or {N(C 6H 4-2-O) 3} 3−

Abstract

(Pentamethylcyclopentadienyl)titanatranes, Cp ∗Ti{(O-2,4-Me 2C 6H 2-6-CH 2) n N(CH 2CH 2O) 3− n } ( n = 0, 1; n = 1, 2; n = 2, 3), featuring three five-membered chelating rings ( 1) to two six-membered chelating rings ( 3) in a stepwise fashion through 2 were synthesized from the corresponding tri-hydroxy chelating ligands 1L– 3L, respectively, using Cp ∗TiCl 3 and triethylamine. Cp ∗Ti{(O-2-C 6H 4) 3N} ( 4) having three five-membered chelating rings from fully deprotonated N(C 6H 4-2-OH) 3 ( 4L) was also synthesized. X-ray analysis shows that 2 and 4 have slightly distorted trigonal bipyramidal geometry around Ti. These compounds exhibited good catalytic activity for the syndiospecific polymerization of styrene in the presence of MAO at various polymerization conditions.