Reversible Size Modification of Iron and Gallium Molecular Wheels: A Ga₁₀ “Gallic Wheel” and Large Ga₁₈ and Fe₁₈ Wheels

Wheelin' and dealin': The M10 molecular wheels [M10(OMe)20(O2CR)10] (M=Ga, R=Me; M=Fe, R=Ph) were modified to M18 wheels in a nontemplate synthesis upon incorporation of a diolate ligand (see space-filling model of [Ga18(pd)12(pdH)12(O2CMe)6(NO3)6]6+; Ga yellow, O red, N blue, C gray; pdH2=1,3-propanediol). Remarkably, dissolution in MeOH converts both M18 wheels back into the M10 wheels.