Incorporation of Boron, Aluminum, and Gallium Derivatives into [{Ti(η⁵-C₅Me₅)(μ-O)}₃(μ₃-CR)] (R = H, Me)

The synthesis and characterization of a family of alkyl and halide adducts of group 13 elements (B, Al, Ga), containing the μ3-alkylidyne oxo derivative ligands [{Ti(η5-C5Me5)(μ-O)}3(μ3-CR)] [R = H (1), Me (2)], are presented. The compounds are synthesized by Lewis acid−base reactions involving equimolecular amounts of 1 or 2 and alkyl [AlR′3] (R′ = Me, Et, Ph) or halide derivatives [MX3] (M = B, X = Br; M = Al, X = Cl, Br, I; M = Ga, X = Cl, Br). The novel species [{E3M}(μ3-O)(μ-O)2{Ti(η5-C5Me5)}3(μ3-CR)] (3−8 and 11−21; R = H, Me; M = B, Al, Ga; E = alkyl, halide) exhibit coordination of 1 or 2 through one of the three oxygen atoms of the Ti3O3 ring to the metal center. In the case of the reaction of 2 with 2 equiv of [AlMe3], the complex [{MeAl}(μ3-O)3{Ti(η5-C5Me5)}3(μ3-CCH2−)] (9) containing the naked carbanion μ3-CCH2− was isolated with methane elimination. On the other hand, the derivative [{Br3B}(μ3-O)(μ-O)2{Ti(η5-C5Me5)}3(μ3-CMe)] (11) undergoes cleavage of the trinuclear structure to give [TiBr(η5-C5Me5)}(μ-O){Ti(η5-C5Me5)}(MeCBO2){TiBr2(η5-C5Me5)}] (22). The crystalline structures of some of these products are also included in this paper.