The insertion of oxygen atoms into Ga-Ga and In-In bonds - Formation of the monomeric compounds R2E-O-ER2 [R = CH(SiMe3)(2)] with strongly enlarged angles E-O-E

The tetraalkyldielement compounds R2Ga-GaR2 (1) und R2In-InR2 (2) [R = CH(S iMe3)(2)] reacted with tri methylamine N-oxide by the insertion of oxygen a toms in their element-element single bonds. The products R2E-O-ER2 are mono meric in the solid state due to the high steric shielding by the voluminous bis(trimethylsilyl)methyl groups. As shown by crystal structure determinat ions, the E-O-E bridges have large angles of 142.7 (E = Ga, 3) and 138.6 de grees (E = In, 4) and short separations between the oxygen and the coordina tively unsaturated Ga and In atoms. Both products are extremely hygroscopic .