Reactions of (Me3SiCH2)2AsSiMe3 with Gallium Halides; Crystal Structure and Dynamic NMR Study of the Dimer (((Me3SiCH2)2As)2GaBr)2

摘要

Prior to our recent studies, the only method of preparing organogallium-arsenic compounds was that reported by Coates et al. These authors prepared two mono (arsino) gallanes by the cleavage of a single Ga-C bond in Me3Ga with the As-H bond of a secondary arsine. In our hands, this reaction not only suffered a reduction in efficiency, but also eventually failed to yield the desired products as the substituents on Gallium and Arsenic increased in size. Moreover, the fact that bis-and tris (arsino) gallanes could not be made by this route led us to examine alternative methods of forming the Ga-As bond, viz., the coupling of gallium chlorides with lithium arsenides or silyl arsines. Others have since reported the use of the lithium arsenide method. There is ample precedent for the reaction of silyl substituted main-group elements (E-SiMe) with covalent halides MC1*, to yield an E-M bond and Me3SiCl.