Titanatranes containing tetradentate ligands with controlled steric hindrance

New monomeric titanatranes [GRAPHICS] (Ar = 2,6-di-i-Pr-phenyl; x = 0, 5; x = 1, 6; x = 2, 7; x = 3, 8) were synthesized from the corresponding tetradentate ligands 1-4, respectively, using an equimolar mixture of Ti(O-i-Pr)4 and 2,6-di-i-Pr-phenol. These compounds show the catalytic activity for the ring opening polymerization of I-lactide. (c) 2007 Elsevier B.V. All rights reserved.