Synthesis of mono- and dinuclear cyclopentadienyl-aryloxy titanium(IV) complexes

This paper reports the reactivity of monocyclopentadienyl titanium complexes [Ti(C5R5)Cl-3] (R = H or Me) with phenol and hydroquinones to afford mono- and dinuclear aryloxy derivatives, respectively. The reaction of hydroquinones HO(C6H2XY)OH (X = Y = H, Me; X = H, Y = Me) with [Ti(C5H5)Cl-3] gave red-orange microcrystalline solids of the corresponding dinuclear complexes [{Ti(C5H5)Cl-2}(2){mu-O(C6H2XY)O}] (X = Y = H (1); X = H, Y = Me (2); X = Y = Me (3)) in high yields. However, their dilithium salts Li-2[O(C6H2XY)O] must be used in the treatment with [Ti(C5Me5)Cl-3] to produce the expected dinuclear derivatives [{Ti(C5Me5)Cl-2}(2){mu-O(C6H2XY)O}] (X = Y = H (4); X = H, Y = Me (5); X = Y = Me (6)) as red-orange microcrystals in high yields too. Reaction of [Ti(C5R5)Cl-3] with 4-allyl-2-methoxyphenol (commonly called eugenol) [C6H3(OH)(OMe)(C3H5)] or its lithium salt led to the monoaryloxy complexes [Ti(C5R5)Cl-2{OC6H3(OMe)(C3H5)}] (R = H (7), Me (8)). (C) 1999 Elsevier Science S.A. All rights reserved.