Reactions of Tetrakis[bis(trimethylsilyl)methyl]digallane(4) with Carboxylic Acids — Substituent Exchange and Bridging of the GaGa bond by two Carboxylato Groups

Yellow tetrakis[bis(trimethylsilyl)methyl]digallane(4) 1 reacts with two equivalents of the carboxylic acids RCOOH (R = −C6H5, −p−BrC6H4, −3,5‐Me2C6H3, −CMe3) to yield almost quantitatively colorless products in which two bis(trimethylsilyl)methyl groups are replaced by two carboxylato ligands. As shown by a crystal structure determination with the 4‐bromo‐phenyl derivative (3), the GaGa bond is bridged by both carboxylato groups in a chelating manner. The GaGa distance is shortened to 238.5(2) pm (1: 254.1(1) pm) and the coordination number of the Ga atoms increased to four.