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

This paper reports the reactivity of monocyclopentadienyl titanium complexes [Ti(C5R5)Cl3] (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)Cl3] gave red–orange microcrystalline solids of the corresponding dinuclear complexes [{Ti(C5H5)Cl2}2{μ-O(C6H2XY)O}] (X=Y=H (1); X=H, Y=Me (2); X=Y=Me (3)) in high yields. However, their dilithium salts Li2[O(C6H2XY)O] must be used in the treatment with [Ti(C5Me5)Cl3] to produce the expected dinuclear derivatives [{Ti(C5Me5)Cl2}2{μ-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)Cl3] with 4-allyl-2-methoxyphenol (commonly called eugenol) [C6H3(OH)(OMe)(C3H5)] or its lithium salt led to the monoaryloxy complexes [Ti(C5R5)Cl2{OC6H3(OMe)(C3H5)}] (R=H (7), Me (8)).