Crystallographic and (spectro)electrochemical characterizations of cobalt(II) 10-phenyl-5,15-di-p-tolylporphyrin

Abdou K.D. Dimé , Hélène Cattey , Dominique Lucas , Charles H. Devillers (1)

1 ICMUB - Institut de Chimie Moléculaire de l'Université de Bourgogne [Dijon]

The synthesis, cyclic and rotating disk electrode voltammograms, UV-visible absorption and Xray diffraction analyses of cobalt(II) 10-phenyl-5,15-dip -tolylporphyrin (1-Co) are described. 1-Co was crystallized by slow diffusion of n-hexane into a concentrated CH2Cl2 solution. X-ray diffraction analyses reveals porphyrin aromatic cycle stacking in the crystal, C-H•••π interactions of the CH2Cl2 solvent with the π-system of one tolyl group and Co(II)•••π (porphyrin ring) interactions. The abstraction of 1.0 F/mol during the electrolysis at the first oxidation potential was followed by spectroelectrochemistry. It leads to the Co(II) → Co(III) transformation rather than the formation of the cation radical of the porphyrin ligand. These results were supported by comparison of the cyclic and rotating disc electrode voltammograms, of the UV-Visible absorption spectra, before and after electrolysis of 1-Co.

Mots clés: X-ray crystallographic structure; Cobalt; Porphyrin; Electrosynthesis; stacked aromatics dimers; C-H•••pi interactions; Co(II)•••pi interactions

Domaines: Chimie de coordination; Chimie analytique; Chimie organique; Matériaux

Abdou K.D. Dimé, Hélène Cattey, Dominique Lucas, Charles H. Devillers. Crystallographic and (spectro)electrochemical characterizations of cobalt(II) 10-phenyl-5,15-di-p-tolylporphyrin. Journal of Molecular Structure, 2021, 1226, pp.129321. ⟨10.1016/j.molstruc.2020.129321⟩. ⟨hal-03419626⟩