Novel dinuclear metal complexes with the general formula [(Me2M){NC5H4 C(R)NNC6H5}-(MMe3)] (M = Al, R = CH3 (1); M = Ga, R = CH3 (2); M = Al, R = H (3); M = Ga, R = H (4)) result when 2-pyridinecarboxaldehyde phenyl hydrazone ligands are mixed with trimethylaluminum and -galbium. The decagallium complex (GaMe2)(8)(GaMe)(2)(mu(4)-O)(2)(mu(3)-O)(4)(C12H10N3)(2) (5) was isolated during the synthesis of 4 as a minor orange product. Three dinuclear metal compounds of the general formula [(Me2M)(SC4H3CHNNC6H5)](2) (M = Al (6); M = Ga (7); M = In (8)) were synthesized by the methane elimination reaction of thiophenecarboxaldehyde phenylhydrazone with trimethyl aluminum, -gallium, and -indium. The mu 4-oxo complex [(Me2In)(2)(OC4H3CH NNC6H5)](2)O (9) was prepared via the reaction of furancarboxaldehyde phenylhydrazone with trimethylindium. The X-ray crystal structures of 1, 4, 5, 7, and 9 are described. The structural data revealed that 5 is a decanuclear gallium compound that contains an eight-membered Ga4O4 cyclic core and that 9 is a tetranuclear indium compound with a weak interaction between the pendant furan and the indium center.