Synthesis and Characterization of Cationic Low-Valent Gallium Complexes of Cryptand[2.2.2]

The synthesis and characterization of two bimetallic, cationic low-valent gallium-cryptand[2.2.2] complexes is reported. The reaction of cryptand[2.2.2] with Ga2Cl4 gave two different cations, [Ga3Cl4(crypt-222)](+) (1) or [Ga2Cl2(crypt-222)](2+) (2), depending on whether or not tri-methylsilyl triflate (Me3SiOTf) was added as a co-reagent. Complexes 1 and 2 are the first examples of bimetallic cryptand[2.2.2] complexes, as well as the first low-valent gallium-cryptand[2.2.2] complexes. Computational methods were used to evaluate the bonding in the gallium cores.