Semi‐empirical molecular orbital studies of porphine and phthalocyanine derivatives, to simulate their intermolecular interactions

Gound‐state electronic properties of porphine, phthalocyanine, and their derivatives, photosensitizers with potential use in the photodynamic therapy of tumors, were studied by semiempirical ( MNDO ) molecular orbital calculations. Geometry, bond orders, electron populations, and net atomic charges were analyzed. The obtained models were applied to study the intermolecular interactions of these molecules utilizing a classical mechanics approach. The dimerization characteristics of different derivatives were obtained by a separate evaluation of the contribution of electrostatic and steric factors.