Abstract: During the investigation of the relative orientation between donor and acceptor in weak CT-complexes, it has been noticed that the electrostatic action between molecules should be considered much more. Based on the analysis of thin crystal structures, a “head-to-head” geometrically matching model has been proposed. From the analysis of the energy of action between donor and acceptor using this model and the measurement of the equilibrium constants, it has been found that when homologous donors act with sameacceptor, because of the geometrical match effect, the stability of the ground state of the complex does not change monotoneously with the asending serial number of donor wheras the stabilities at the ends of the given donor series are smaller and the largest stability presents in middle.
In IR spectra, a similar trends of relative intensity of some adsorption peaks been observed.