The use of polarization methods for studying the self-assembly of molecules makes it possible to determine the nature of the hypochromic effect observed in their electronic spectra. The main condition for self-assembly is the formation of a high-molecular local volume. Depending on environmental conditions, the process of self-assembly of organic compounds can occur due to hydrophobic, hydrophilic, Coulomb, van der Waals forces or hydrogen bonds. The complexity of studying the process of self-assembly of molecules in solutions dictates the development of new optical cells and modern methods for calculating complex spectra. As a result, which manifest the ability to interpret complex spectra.The monograph is intended for a wide range of researchers, young scientists, teachers, doctoral students and undergraduate students specializing in the field of condensed matter physics.