INDUCTIVE AND MESOMERIC EFFECTS IN SUBSTITUTED FULVENE AND PYRIDINE DERIVATIVES

The electronic charge distribution in substituted fulvene and pyridine derivatives is examined using the simple Hückel molecular orbital method. Parameters characterizing the electronegativity of the substituent and the carbon to which it is linked are varied in order to cover actually existing substituents.It is found that the nature of the inductive and mesomeric effects is not basically different from that in the case of benzene. The most negative sites in fulvene show a certain variation with the place of substitution. In pyridine they are the ortho and para carbons for meta substitution and the meta carbons for ortho and para substitution.