Aluminum, gallium and indium thiobenzoates: synthesis, characterization and crystal structures

Compounds R2M[S(O)CPh] [where R = tBu, M = Al (1); R = tBu, M = Ga (2); R = Me, M = Ga (3)] have been synthesized in reactions of R3M with thiobenzoic acid in a 1:1 molar ratio of reagents. The reaction of Me3Ga with three equivalents of thiobenzoic acid yielded the compound Ga[S(O)CPh]3 (4), in which thiobenzoate moieties act as bidentate SO ligands. In the presence of Et3N, InCl3 reacted with thiobenzoic acid with formation of an ionic compound {In[S(O)CPh]4}(HNEt3)+ (5). The thiobenzoate ligands are bonded with the metallic center via the sulfur atoms only. The compounds 4 and 5 have been structurally and thermally studied. The thermal decomposition pathways of compounds 4 and 5 are proposed.