Crystal structures of titanium-aluminium and -gallium complexes bearing two μ 2 -CH 3 units

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