Spectra and structure of gallium compounds: Part III. vibrational studies of trimethylgallane-phosphine and trimethylgallane-phosphine-d3

Abstract The IR (80–4000 cm −1 ) and Raman (50–3500 cm −1 ) spectra of (CH 3 ) 3 GaPH 3 and (CH 3 ) 3 GaPD 3 have been recorded for the solid state at low temperature. The spectra are interpreted on the basis of C 3v molecular symmetry. A modified valence force field model is utilized in calculating the frequencies and the potential energy distribution. The calculated potential constants for the adducts are compared to those previously reported for the Lewis base moiety, and the differences are shown to be consistent with structural changes upon adduct formation. Only very minor coupling is found between the Ga-C 3 stretches and the CH 3 deformations and the remaining normal modes are nearly pure. The relative values of the force constants are compared to the corresponding quantities in other Group IIIA-Group VA coordinated complexes.