Group 13 organometallic chalcogen derivatives: their structures and behavior in solution

The syntheses, structures and equilibria which occur for 13–16 organometallic compounds are reviewed. The organoaluminum thiolates form dimers, trimers, and tetramers with central (AIS)₂, (AIS)₃, and (AIS)₄ rings in the solid state. The structures of the gallium and indium thiolates are dominated by dimers, but a tetramer has been observed for gallium and a trimer for indium. Only dimeric derivatives have been reported for the selenium and tellurium derivatives. In hydrocarbon solutions, the aluminiun thiolates establish equilibria between different aggregates and conformations with dimers and trimers most common. In the dimeric derivatives, [Me₂Al(μ-SME)]₂ and [Me₂Al(μ-SeMe)]₂, syn and anti conformations are observed in solution at low temperature by NMR spectroscopy. In the trimeric derivatives, the chair conformation is observed in the solid state. In solution, a chair to chair inversion occurs with the rate dependent on the substituents bound to the sulfur.