Vibrational spectrum of 4-fluoraniline

The Raman spectrum of 4-fluoraniline (4FA) has been recorded, the quadratic force field has been calculated at RHF/6-31 divided by G(*) level of theor y and then scaled to reproduce the experimental frequencies, by using Pulay 's scaled quantum mechanical force field (SQMFF) methodology. Likewise, DFT force field has been calculated at the B3LYP/6-31 + G* level. On the basis of all these results, a general assignment of the vibrational spectra of 4 FA has been proposed and compared with that of aniline in order to determin e the substitution effect of the fluorine atom. (C) 2001 Elsevier Science B .V. All rights reserved.