Ab initio quantum-mechanical investigations have been carried out to examine the effects of substituents on structural deformations and electronic properties. We have studied eight substituent groups: two electron donor groups (-NH2, -N(CH3)(2)) and six electron acceptor groups (-NO2, -BCl2, -BF2, -BH2, -CN, and -NC). These groups have been used to provide 12 different donor-acceptor combinations. As the donor strength increases from -NH2 to -N(CH3)(2), the change of the electronic properties shows the same trend for all accepters. It has been shown that a constant like a Hammett constant exists and it can be used for the prediction of electronic properties.