Out-of-Plane CH Vibrations of Benzene Derivatives

Abstract

The normal coordinate treatment is made of the infrared active out-of-plane CH vibrations for various benzene derivatives. Frequencies calculated with the use of the out-of-plane force constants for benzene are in good agreement with the observed values. Intensities of these bands are also dealt with. The result confirms that the CH bond has the sign of polarity opposite to that of the carbon-halogen bonds.