MATRIX-ISOLATION SPECTROSCOPIC STUDY OF THE 1 1 COMPLEXES OF TRIMETHYLGALLIUM WITH GROUP-VI ALKYLS/

The 1/1 molecular adducts of trimethylgallium with group VI dimethyl b ases (CH3)2X (X = O, S, Se) have been isolated and spectroscopically c haracterized for the first time in argon matrices. Perturbed vibration al modes of a number of the acid and base subunits were observed. Remo val of degeneracy of the E modes of (CH3)3Ga and activation of the GaC 3 Stretching mode indicate a reduction in symmetry for the complex. Th e magnitudes of the shifts of the C-O-C stretching modes of (CH3)2O we re compared to those of previously studied complexes of dimethyl ether and used to qualitatively determine an order of acidity for a range o f Lewis acids, including (CH3)3Ga.