Self-assembling cobalt(II) porphyrin-fullero [60]pyrrolidine triads. Synthesis and spectral properties in the ground and excited state

Meso-4-Trifluoromethylphenyl substituted cobalt(II)porphin, CoT(CF3P)P, and its coordination 1: 2 com-plex (triad) with 1-N-methyl-2-(pyridin-4-yl)-3,4-fullero [60]pyrrolidine, (PyC60)(2)CoT(CF3P)P, were firstly synthesized and the properties of their molecular solutions were studied. The chemical structure of CoT(CF3P)P and triad was fully confirmed by the UV-vis, IR and H-1 NMR spectroscopy and mass spec-trometry methods. The triad formation mechanism as the two-step equilibrium characterized by equilib-rium constant K- 1 (5.89 +/- 1.50) x 10( 4) M -1 and K- 2 (7.40 +/- 1.66) x 10 5 M -1 was revealed. Using femtosec-ond pump-probe spectroscopy measurements, the photoinduced electron transfer in the synthesized triad was described. The excited state lifetime of the precursors, CoTPP, CoT(CF3P)P and the charge separated state lifetime of (PyC60)(2)CoT(CF3P)P compared with unsubstituted (PyC60)(2)CoTPP were determined. It was established that the CF3 groups in the porphyrin periphery slightly change the CoTPP/CoT(CF3P)P excited state lifetime and the electron transfer rate constant in the correspondent triads. (C) 2022 Elsevier B.V. All rights reserved.

Automated summary

This article describes the synthesis of meso-4-trifluoromethylphenyl substituted cobalt(II)porphin and its coordination complex, as well as the study of their molecular properties. The chemical structures were confirmed using UV-vis, IR, H-1 NMR spectroscopy, and mass spectrometry. The mechanism of triad formation and photoinduced electron transfer process were investigated.