Application of density functional theory to metal-containing radicals Study of the organometallic radicals GeH, GeCH3 and GeC2H5

Abstract

Geometric parameters, harmonic frequencies and absolute energies have been calculated for the ground and first excited states of the organometallic radicals GeH, GeCH₃ and GeC₂H₅ using the B3PW91/6-311G* level of theory. Dipole moments are also provided. Selection of this theoretical method was based on comparison between the experimental data for GeH and computational results for a number of different abinitio and density functional (DFT) models. The B3PW91 model was superior to any of those we employed, including the more widely used B3LYP method. The DFT results are in better agreement with experiment than are the abinitio results, even with extensive CI calculations, and require only a fraction of the computational resources. The results are expected to be useful in the spectroscopic monitoring of chemical vapour deposition (CVD) processes involving germane and tetramethylgermane, two common precursors, as well as in the continuing fundamental study of organometallic radicals.