translate English to French: The spectral bands have been assigned as due to π,R(3s), π,π*, and π, R(3p) excitations on the basis of their term values and the differences between their intensities in the solution and gas phase absorption spectra.
En se basant sur les valeurs de leurs termes ainsi que sur les différences entre les intensities de leurs spectres d'absorption en solution et en phase gazeuse, on a attribué les bandes spectrales aux excitations π,R(3s), π,π* et π,R(3p).