The electronic structures and the non-linear optical properties of some asymmetrically substituted phthalocyanines have been studied using the AM1 method. The results show that there is some regularity between the dipole moment μ, the energy difference of frontier orbital △E~D~A, charge transfer △Q~D~A and the non-linear optical coefficient β. The relationship betwecn μ and β is similar to the that between △E~D~A and β.

Key words: PHTHALOCYANIN (=PHTHALOCYANINE), ELECTRONIC STRUCTURE, NON LINEAR OPTICS, CHARGE TRANSFER, FRONTIER ORBITAL THEORY