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

Yellow tetrakis[bis(trimethylsilyl)methyl]digallane(4) 1 reacts with two equivalents of the carboxylic acids RCOOH (R = −C 6 H 5 , − p −BrC 6 H 4 , −3,5‐Me 2 C 6 H 3 , −CMe 3 ) 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 GaGa bond is bridged by both carboxylato groups in a chelating manner. The GaGa distance is shortened to 238.5(2) pm ( 1 : 254.1(1) pm) and the coordination number of the Ga atoms increased to four.