**4. Conclusions**

Thus, the obtained porphyrin oligomers and polymers in solid state and in solution are compounds in which the porphyrin fragments with tyrosine and diaminoresorcinol axial ligands form stable coordination compounds with two five-membered square planar metallocycles. Soluble products of the chelation of Sn(IV)-tetra(sulfonatophenyl)porphyrin diaxial complexes with Cu2+ are porphyrin coordination oligomers with different numbers of tetrapyrrole fragments (from two to six). The specific composition of the interaction products depends on the concentration ratio of the reagents. If, at an equivalent concentration ratio of the reagents, the main products are porphyrin dimers, then an excess of Cu2+ leads to the formation of larger oligomeric porphyrin arrays. The obtained porphyrin oligomers formed by five-membered chelate rings with Cu2+ are stable compounds (in comparison with oligomers, which can be formed by four- or six-membered chelate rings based on copper cations). The results show that chelation of Sn(IV)-porphyrin diaxial complexes with Cu2+ is accompanied by an increase in the fluorescence of the resulting hybrid organic-inorganic oligomers. The results obtained are of particular interest to those involved in creating of new 'chemo-responsive' (i.e., selectively interacting with other chemical species as receptors, sensors, or photocatalysts) materials, the optoelectronic properties of which could be controlled by varying the number of monomeric fragments in the polyporphyrin arrays.

**Author Contributions:** Conceptualization and Methodology, N.Z.M. and I.A.K.; Investigation, G.M.M., A.E.E. and D.A.L. All authors have read and agreed to the published version of the manuscript.

**Funding:** N. Mamardashvili and G. Mamardashvili thank for financial support the Russian Foundation for Basic Research, project No. 19-03-00078 A (part Synthesis and identification of new coordination oligomers and polymers of Sn(IV)-tetra-(4-sulfonatophenyl)porphyrin) and the Russian Science Foundation, project No. 19-73-20079 (part Studies of monomeric fragments number influence on the optoelectronic properties of synthesized polyporphyrin arrays).

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Samples of the compounds are available from the authors.

**Acknowledgments:** This research was implemented on the equipment of the Center for the Joint Use of Scientific Equipment of the Institute of Organic Chemistry of the Russian Academy of Sciences and the Upper Volga Region Center of Physicochemical Research.

**Conflicts of Interest:** The authors declare no conflict of interest.
