Trimethylaluminum dimer structure and its monomer radical cation: A density functional study

Molecular structures, energies, vibrational frequencies, and dissociation energies for Al(CH3)(3), Al(CH3)(3)(+), and [Al(CH3)(3)](2) have been studied using density functional and Moller-Plesset perturbation methods. The calculated properties are compared with the available experimental results. All the methods correctly describe the geometries of the neutral molecules. Density functional or MP2 (or MP4) methods provide similar ionization energies, whereas the dissociation energy of the dimer is more dependent on the methodology.