An extensive vibrational analysis of ethyl benzoate (EB) and its titanium tetrachloride complexes (1) has been performed. The phenyl force field was constructed by expanding a slightly modified Pulay-Fogorasi-Boggs benzene field (2) in three steps, through bromo-benzene, benzoic acid, and finally the ester (3). A good fit to the observed frequencies and splitting of the degenerate benzene vibrations was emphasized in all three steps.
"A Comment To The Expansion Of Benzene Force Fields", Proc. SPIE 1145, 7th Intl Conf on Fourier Transform Spectroscopy, (1 December 1989); doi: 10.1117/12.969497; https://doi.org/10.1117/12.969497