Synthesis, Characterization, and Electrochemistry of Open-Chain Pentapyrroles and Sapphyrins with Highly Electron-Withdrawing meso -Tetraaryl Substituents

Abstract : A series of open-chain pentapyrroles and sapphyrins with highly electron-withdrawing substituents (i.e., CN, CF3 , or CO2 Me) on the meso-phenyl rings was synthesized and characterized as to the spectral properties, protonation reactions, and electrochemistry in non-aqueous media. The investigated compounds are represented as (Ar)4 PPyH3 and (Ar)4 SapH3 where PPy and Sap correspond to the tri-anion of the open-chain pentapyrrole and sapphyrin, respectively, and Ar=p-CNPh, p-CF3 Ph, or p-CO2 MePh. UV/Vis and 1 H NMR spectroscopy as well as mass spectrometry data are given for the confirmation of the structures for the newly synthesized compounds. An X-ray structure for one of the pentapyrroles, that is, (p-CF3 Ph)4 PPyH3 (2), is also presented. The protonation processes were examined by UV/Vis absorption spectroscopy during the titration of the compounds with trifluoroacetic acid (TFA) in CH2 Cl2 . Equilibrium constants for the protonation reactions were calculated by using both the Hill equation and the mole ratio method. The protonation-initiated conversion of pentapyrroles to sapphyrins upon oxidation was also investigated. Cyclic voltammetry was used to measure the redox potentials in CH2 Cl2 , PhCN, and/or pyridine (Py). Electrochemical properties, protonation constants, and chemical reactions of the six compounds in the two series were then analyzed as a function of the solvent properties and the type of the electron-withdrawing groups on the meso-phenyl rings.
Type de document :
Article dans une revue
Chemistry - A European Journal, Wiley-VCH Verlag, 2017, 23 (52), pp.12833 - 12844. 〈http://onlinelibrary.wiley.com/doi/10.1002/chem.201701968/abstract〉. 〈10.1002/chem.201701968〉
Domaine :
Liste complète des métadonnées

https://hal-univ-bourgogne.archives-ouvertes.fr/hal-01589768
Contributeur : Icmub - Université de Bourgogne <>
Soumis le : mardi 19 septembre 2017 - 09:18:57
Dernière modification le : vendredi 6 juillet 2018 - 15:06:09

Identifiants

Citation

Wenqian Shan, Nicolas Desbois, Virginie Blondeau-Patissier, Mario L. Naitana, Valentin Quesneau, et al.. Synthesis, Characterization, and Electrochemistry of Open-Chain Pentapyrroles and Sapphyrins with Highly Electron-Withdrawing meso -Tetraaryl Substituents. Chemistry - A European Journal, Wiley-VCH Verlag, 2017, 23 (52), pp.12833 - 12844. 〈http://onlinelibrary.wiley.com/doi/10.1002/chem.201701968/abstract〉. 〈10.1002/chem.201701968〉. 〈hal-01589768〉

Partager

Métriques

Consultations de la notice

79