CALCULATIONS OF THE STRUCTURE AND THE VIBRATIONAL INFRARED FREQUENCIES OF SOME METHYLPHOSPHONATES

We have calculated the energies, the optimized geometries and the vibrational infrared frequencies of methylphosphonic acid and three of its esters, namely the dimethyl ester, the diethyl ester and the diisopropyl ester. All computations are performed with the Gaussian 90 Program Package, utilizing both the 3-21G and the 6-31G* basis sets. We compare the computed vibrational frequencies and the corresponding IR and Raman intensities with the experimental data and we derive two different sets of correction factors that should be applied either to the 3-21G or to the 6-31G* computed frequencies. © 1992, Taylor & Francis Group, LLC. All rights reserved.