Methyl-hydride metathesis between [Zr(cp)(2)Me(2)] and [HAl(mu(3)-NBu(t))](4): Molecular structures of [Me(1-x)H(x)Al(mu(3)-NBu(t))](4) (x=0, 0.78 or 1) and [(cp)(2)ZrMe(mu-H)](2) (cp=eta(5)-C5H5)

The reaction of [Zr(cp)(2)Me(2)] (cp = eta(5)-C5H5) with the cubane iminoalane, [HAl(mu(3)-NBu(t))](4), yielded [(cp)(2)ZrMe(mu-H)](2) and the alkyl-substituted iminoalanes [Al(4)MeH(3)(mu(3)-NBu(t))(4)] 1 and [Al(4)Me(2)H(2)(mu(3)-NBu(t))(4)] 2. The dimer [(cp)(2)ZrMe(mu-H)](2) decomposes above 60 degrees C. The methyl-hydride exchange is first, order with respect to each reactant concentration, and Delta H-double dagger and Delta S-double dagger have been determined as 104(1) kJ mol(-1) and 18.8(4) J K-1 mol(-1), respectively. The molecular structures of [(cp)(2)ZrMe(mu-H)](2), [HAl(mu(3)-NBu(t))](4), [MeAl(mu(3)-NBu(t))](4) and a cocrystallization disorder of compounds 1, 2 and [HAl(mu(3)-NBu(t))](4) have been determined by X-ray crystallography.