A gas-phase Raman study of trimethylaluminium and trimethylboron monomers

Gas-phase Raman data are reported for trimethylaluminium. The dimer–monomer equilibrium which exists in the vapour phase was observed over the temperature range 70–290°C and from these data, bands associated with dimer and monomer are easily assigned. The data for trimethylaluminium monomer are very similar to that of gaseous trimethylboron and are consistent with that expected for a planar D3h molecule. Trends which exist in that MMe3 series where M = B, Al, Ga, and In are briefly discussed.