Reactions of tetraalkyl dialuminium(4), digallium(4) and diindium(4) compounds with 3-chloroperbenzoic acid: Cleavage of the element-element bonds and formation of mu-carboxylato-O,O'-mu-hydroxo dielement derivatives

Tetrakis [bis(trimethylsilyl)methyl] dialane(4) 1, -digallane(4) 2 und -diindane(4) 3 with the elements Al, Ga, and In in the unusual oxidation state of +2 react with 3-chloroperbenzoic acid by the cleavage of their element-element single bonds. As shown by crystal structure determinations of the Ga (5) and In derivative (6), the products exhibit two dialkylelement fragments bridged by a mu-hydroxo and a mu-carboxylato-O,O' group in the solid state. Their formation can be described by an insertion of the low valent Al, Ga, or In atoms into the peroxo group. Only the constitution of the Al compound 4 remains unchanged in solution, while the Ga and In analogs partially dissociate to form the compounds R2E(mu-OH)(2)ER2 and R2E(O2CR') (E = Ga or In, R=CH(SiMe3)(2), R'=-3-Cl-C6H4), which all were synthesized and isolated in a pure form by other routes.