Study of the Influence of the Nature and Position of the Halogen Atom in the N-Halogenophenyl-2,5-dimethylpyrrole upon the Vibrational (Hyper) polarizability:Theoretical Study

摘要

The two contributions,vibrational and electronic,to the electrical properties polarizability and first hyperpolarizability of the N-[(2,3,OR 4)-fluorophenyl]-2,5-dimethylpyrrole are evaluated theoretically at the HF/6-31G level within the double harmonic oscillator approximation.The calculations demonstrate that,with the exception of the second harmonic generation,the vibrational contribution to the first hyperpolarizability is important.However,the vibrational polarizability,contributes at most,10% to the total electric polarizability.The analysis upon the sum-over-states expressions shows that there are only few modes which contribute strongly and,generally,have small vibrational energies.The effect of the fluorine substitution by an other substituent is also adressed.