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

Abstract

(Pentamethylcyclopentadienyl)titanatranes, Cp*Ti{(O-2,4-Me2C6H2-6-CH2)(n)N(CH2CH2O)(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*TiCl3 and triethylamine. Cp*Ti{(O-2-C6H4)(3)N} (4) having three five-membered chelating rings from fully deprotonated N(C6H4-2-OH)(3) (4L) was also synthesized. Xray 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. (C) 2008 Elsevier B. V. All rights reserved.