Dipole moment derivatives and infrared intensities. IV. Prediction of absolute infrared intensities of the fundamental vibrations of CF2 and CF3 radicals

Abstract

Absolute infrared intensities have been predicted for the fundamental absorption bands of CF2 and CF3 radicals, using an F atomic polar tensor transferred from CH3F. The predicted relative intensities have been compared with the experimental spectra of the matrix-isolated radicals with satisfying results. The effect on the predictions resulting from modification of the transferred polar tensor is examined by using F atom polar tensors from CF2H2 and from CNDO/2 and INDO calculations. The scatter of the predicted values suggests that the predictions of the absolute integrated molar absorption coefficients may be expected to be accurate within a range of about ±30%, and so would be of potential use in semiquantitative analytical applications.