CNDO CI study of electronic structure and geometry in ground and excited states. ortho- and meta- difluorobenzenes

Abstract

The modified CNDO/2 method (CNDO/s) has been applied to study the electronic structure and geometry of ortho- and meta-difluorobenzenes in their ground and first excited singlet states. Calculated density matrices have been transformed into σ- and π-bond orders by the technique suggested earlier. Bond lengths have been calculated using the Coulson bond-orderbond-length relationship and the bond angles were assumed to the 120° in both states of these molecules. The calculated rotational constants are in very good agreement with the experimental measurements recently reported by Hartford and Lombardi. © 1973.