Vibrational analysis of substituted benzonitriles. III. Transferability of force constants--the case of some halogeno-, methoxy- and nitro-benzonitriles.

A zero-order normal coordinate analysis of both the in-plane and out-of-plane vibrations was made for 2-chloro, 6-fluorobenzonitrile, s-trichlorobenzonitrile, p- and m-methoxybenzonitriles and m-nitrobenzonitrile, transferring the force constants from our earlier work. The observed and calculated frequencies agree with an average error of 16.8 cm-1, demonstrating the transferability of the force constants obtained previously. On the basis of calculated potential energy distributions and eigenvectors, several assignments suggested by earlier workers have been revised.