Geometric and electronic structure of p-ethoxycarbonylphenyl-dialkylphosphines

The geometry and the spectral characteristics of p-ethoxycarbonyl-phenyldialkylphosphines were interpreted by using the modified neglect of diatomic overlap method and the spectroscopic variant of the complete neglect of differential overlap method with the same parameters. The characteristics of the electronic transitions for conformers of p-COOHC6H4PMe2 calculated by the CNDO/S method were presented. Calculations for the p-COOHC6H4MNe2 molecule were performed for comparison. IR and Raman spectroscopy were conducted on the conformers and results are presented; the appearance of the p-pi conjugation of the dimethylphosphino group with the phenyl ring and the ethoxy carbonyl group in the gonal conformation was weaker than for the dimethylamino group by a factor of two, and 3-4 times weaker if conformational equilibrium is not taken into account