TRANSFERABLE VALENCE FORCE-FIELDS FOR SUBSTITUTED BENZENES .4. DINITROBENZENES

A zero-order normal. coordinate analysis of both the in-plane and out-of-plane vibrations was made for p-, m- and o-dinitrobenzenes, 1-fluoro-, 1-chloro- and 1-bromo-2,4-dinitrobenzenes, transferring the force constants from our earlier work. The observed and calculated frequencies agree with an average error of 15.6 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.