Gallium−Gallium Bonds as Key Building Blocks for the Formation of Large Organometallic Macrocycles, on the Way to a Mesoporous Molecule

A macrocyclic gallium carboxylate (3) is formed on reaction of the digallane(4) R2Ga−GaR2 [R = CH(SiMe3)2], 1, with naphthalene-2,6-dicarboxylic acid, HOOC−C10H6−COOH. The macrocycle comprises 44 atoms, and four Ga−Ga single bonds are connected by four dicarboxylato bridges. The cavity of the heterocycle may be described as a rigid molecular square possessing a largest diameter of 1.86 nm. It encloses four 1,2-difluorobenzene molecules.