Complex Formation of Cobalt(II) Octakis(3,5-di-tert-butylphenoxy)phthalocyanine with 2′-(Pyridin-4-yl)-5′-(Pyridin-2-yl)-1′-(Pyridin-2-ylmethyl)-2′,4′-Dihydro-1′H-Pyrrolo[ 3′,4′:1,2][C60-Ih][5,6]fullerene

Abstract

The formation of the donor–acceptor complex of cobalt(II) octakis(3,5-di-tert-butylphenoxy)phthalocyanine with 2′-(pyridin-4-yl)-5′-(pyridin-2-yl)-1′-(pyridin-2-ylmethyl)-2′,4′-dihydro-1′Hpyrrolo[3′,4′ : 1,2][C₆₀-I_h][5,6]fullerene (Py₃C₆₀) in toluene was studied by chemical kinetics (thermodynamics) and spectroscopy methods in comparison with a similar system based on 4-picoline (Pic). In both cases, the reaction occurred in one step giving donor–acceptor complexes of 1 : 1 stoichiometry, which were characterized by key spectral (UV-vis, IR, ¹H NMR) parameters and thermodynamic equilibrium parameters; in the case of reaction with pyridyl-substituted fullerene, full kinetic description was obtained. The stability constants for (Pic)CoPc(3,5-^tBuPhO)₈ and (Py₃C₆₀)CoPc(3,5-^tBuPhO)₈ are (1.01 ± 0.16) × 10⁴ L/mol (logK = 4.00, ΔG=–22.84 kJ/mol) and (1.84 ± 0.16) × 10⁵ L/mol (logK = 5.26, ΔG=–30.04 kJ/mol), respectively. The obtained results are relevant for the development of new efficient components for photovoltaic cells based on phthalocyanine–fullerene systems.