Equilibria and Rates of Formation of New Donor-Acceptor Systems Based on the Porphyrin Complex of Cobalt(II) and Fulleropyrrolidine

Abstract

Donor-acceptor systems containing metalloporphyrin as an electron-donor component exhibit the property of photoinduced electron transfer (PET), which makes them promising in obtaining materials for optoelectronics. In a search for new perspective systems with PET we have performed experimental studies of interactions between the newly synthesized (5,15-bis(4,6-dichloropyrimidin-5-yl)-10,20-bis(2,4,6-trimethylphenyl)porphinato)cobalt(II) (CoPCl₄) and 1-methyl-2-(pyridin-4'-yl)-3,4-fullero[60]pyrrolidine (PyC₆₀) in toluene at 298 K. The process parameters were obtained, and a complete kinetic description is presented. The process occurs stepwise as reversible and irreversible reactions and ends with the formation of the donor-acceptor triad (PyC₆₀)₂CoPCl₄ via the formation of an intermediate product—the dyad (PyC₆₀)CoPCl₄. The composition and structure of the triad are substantiated using UV-visible, IR, and ¹H NMR spectroscopy and MALDI-TOF mass spectrometry data. A comparative analysis was performed of the quantitative parameters of the (PyC₆₀)₂CoPCl₄ formation reaction with those for structural analogs previously described in the literature; the formation constants of the triads were correlated with their structure, which is important for fine tuning of the properties of functional materials based on them.