Abstract
The complex formation of metal ions with polymers is of great interest for the development of new materials used in catalytic processes, sorption, and electrochemistry. Particular attention is given to cobalt (II), which can form complexes with nitrogen- and oxygen-containing polymers such as polyacrylic acid (PAA), polyacrylamide (PAAm), chitosan (Chit), and poly-4-vinylpyridine (P4VP). The aim of this study is to investigate the complexation processes of cobalt (II) ions with the functional groups of these polymers, as well as to determine the stability and nature of the resulting complexes. Results and Discussion. It has been established that the stability of polymer-metal complexes is determined by the nature of the functional groups of the polymers and the interaction mechanism. PAA-Co complexes demonstrated the highest stability due to the covalent binding of cobalt ions with the carboxyl groups of PAA. At the same time, PAAm-Co and P4VP-Co complexes exhibited lower stability, which is associated with a donor-acceptor interaction mechanism. The shift in the characteristic absorption bands of the functional groups of the polymers upon their interaction with cobalt ions indicates the formation of polymer-metal complexes with different binding mechanisms. For PAAm, the shift in absorption bands confirmed the donor-acceptor interaction mechanism. Conclusion. The obtained data confirm the interaction mechanism of cobalt ions with the functional groups of polymers, as well as the different nature of binding. Thus, the results open up prospects for the use of polymer-metal complexes in the creation of materials for catalytic applications.