Skip to Main content Skip to Navigation
Journal articles

Exploring the redox reactivity of magnesium porphine. Insight into the origins of electropolymerisation

Abstract : Magnesium(II) porphine, MgP (1), was synthesised according to the Lindsey procedure allowing to isolate and crystallise 1-formyldipyrromethane (2) as a synthetic intermediate. Unprecedented Xray diffraction studies revealed multiple intermolecular associations in the crystal between neighbouring units of 2, namely hydrogen bond and CH … π. The electrochemical behaviour of 1 was examined by means of cyclic voltammetry. In oxydation, two well-defined and distinct steps are assigned to macrocycle concerned electron transfers yielding initially the π-cation radical and π dication, respectively. The highly reactive dication condenses neutral magnesium porphine to form a diprotonated di-isoporphine species, which is assumed to be a key intermediate at the orig in of the electropolymerisation. Electrolyses were performed at the potential of the π-cation radical generation. Investigation of the electrolysed solution by UV-visible spectroscopy and Maldi-tof spectrometry revealed the presence of several oligoporphyrins, with diporphine as an important product. In all the oligomers series, extensive demetallation is evidenced, due to the increasing acidity of the medium as oligomerisation progresses. This demetallation could be prevented by addition of 2,6-lutidine as a base prior to electrolysis. In the oligomer series, the porphine units seem to be connected through meso-meso bonds, an argument supported by certain features of the UV-visible spectrum. Finally, the mechanism of oxidative oligomerisation is discussed, from the point of view of the initial steps of the electropolymerisation.
Complete list of metadata

https://hal.archives-ouvertes.fr/hal-03420006
Contributor : Charles Devillers Connect in order to contact the contributor
Submitted on : Monday, November 8, 2021 - 10:29:48 PM
Last modification on : Thursday, January 20, 2022 - 11:38:03 AM

File

unmarked_revised_article for H...
Files produced by the author(s)

Identifiers

Collections

Citation

Charles Devillers, Dominique Lucas, Abdou Dime, Yoann Rousselin, Yves Mugnier. Exploring the redox reactivity of magnesium porphine. Insight into the origins of electropolymerisation. Dalton Transactions, Royal Society of Chemistry, 2010, 39 (9), pp.2404. ⟨10.1039/b914916c⟩. ⟨hal-03420006⟩

Share

Metrics

Les métriques sont temporairement indisponibles