ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 30, Number 2
JKCSEZ 30(2)
April 20, 1986 

The Hammett's substituent constants were analyzed for the substituted-benzoic acid, -benzene and -naphthalene by LCAO MO method. Hammett's σ-values have been theoretically proved to treat as the sum of independent contribution of inductive effect and resonance effect. That is, Is (static inductive effect) and Id (dynamic inductive effect) corresponding to inductive effect are chosen as net charge and approximate self atom polarizability indices respectively, and ΔEHOMO which is the difference in HOMO energy level between substituted molecule and unsubstituted molecule as resonance effect. In conclusion, it has been found that the observed σ-values depend on the sum of Id, Is and ΔEHOMO.