A highly stable J-type dimer based on 2-hydroxy-tri(tert-butyl)-substituted zinc phthalocyanine with specific supramolecular architecture was investigated by UV-visible and fluorescence spectroscopy and by cyclic voltammetry to show strong π–π interactions and coordination between hydroxy-groups and Zn²⁺ central metal ions. The possibility of controlling the fluorescent properties of the obtained complex by using different solvents is demonstrated, which, along with the high thermal stability according to the thermoanalytical study, may increase practical applicability of supramolecular dimeric phthalocyanine compounds.