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

Abstract

The synthesis and characterization of a family of alkyl and halide adducts of group 13 elements (B, Al, Ga), containing the μ(3)-alkylidyne oxo derivative ligands [{Ti(η(5)-C(5)Me(5))(μ-O)}(3)(μ(3)-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 [MX(3)] (M = B, X = Br; M = Al, X = Cl, Br, I; M = Ga, X = Cl, Br). The novel species [{E(3)M}(μ(3)-O)(μ-O)(2){Ti(η(5)-C(5)Me(5))}(3)(μ(3)-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 Ti(3)O(3) ring to the metal center. In the case of the reaction of 2 with 2 equiv of [AlMe(3)], the complex [{MeAl}(μ(3)-O)(3){Ti(η(5)-C(5)Me(5))}(3)(μ(3)-CCH(2-))] (9) containing the naked carbanion μ(3)-CCH(2-) was isolated with methane elimination. On the other hand, the derivative [{Br(3)B}(μ(3)-O)(μ-O)(2){Ti(η(5)-C(5)Me(5))}(3)(μ(3)-CMe)] (11) undergoes cleavage of the trinuclear structure to give [TiBr(η(5)-C(5)Me(5))}(μ-O){Ti(η(5)-C(5)Me(5))}(MeCBO(2)){TiBr(2)(η(5)-C(5)Me(5))}] (22). The crystalline structures of some of these products are also included in this paper.