Crystal structures of titanium-aluminium and -gallium complexes bearing two μ2 -CH3 units

The isotypic crystal structures of two titanocene complexes containing an EMe3 unit (E = Al, Ga; Me = meth-yl) with two μ2-coordinating methyl groups, namely [μ-1(η5)-(adamantan-1-yl-2κC1)cycylo-penta-dien-yl]di-μ2-methyl-methyl-2κC-[1(η5)-penta-methyl-cyclo-penta-dien-yl]aluminiumtitanium(III), [AlTi(CH3)3(C10H15)(C15H18)], and [μ-1(η5)-(adamantan-1-yl-2κC1)cycylo-penta-dien-yl]di-μ2-methyl-methyl-2κC-[1(η5)-penta-methyl-cyclo-penta-dien-yl]galliumtitanium(III), [GaTi(CH3)3(C10H15)(C15H18)], are reported. Reacting a dinuclear nitro-gen-bridged low-valent titanium(III) complex with the Lewis acids AlMe3 or GaMe3 results in the loss of mol-ecular di-nitro-gen and the formation of two monomeric titanocene(III) fragments bearing two μ2-bridging methyl groups. Single crystal X-ray diffraction reveals the formation of a new E-C bond involving the penta-fulvene ligand while the bridging and terminal methyl groups remain intact.