Hg(II)-Mediated Tl(I)-to-Tl(III) Oxidation in Dynamic Pb(II)/Tl Porphyrin Complexes

Stéphane Le Gac (1) , Victoria Ndoyom (1) , Luca Fusaro (2) , Vincent Dorcet (1) , Bernard Boitrel (1)

1 ISCR - Institut des Sciences Chimiques de Rennes
2 UNamur - Université de Namur [Namur]

Compared with their purely organic counterparts, molecular switches that are based on metal ion translocations have been underexplored, and more particularly, it remains challenging to control the translocation of several particles in multisite receptors. Recently, bimetallic complexes that undergo double translocation processes have been developed with bis-strapped porphyrin ligands. To implement a redox control for these systems, we have investigated the formation of heterobimetallic lead/thallium complexes, with thallium in the +I and +III oxidation states. Two different complexes were characterized: 1) a Pb /Tl complex, in which both metal ions interact with the N-core on its different sides, and 2) a Pb /Tl complex with Tl selectively bound to the N-core and Pb selectively bound to the strap opposite to Tl . These two complexes undergo interconversion between their two degenerate forms (same coordination of the metal ions but on opposite sides) by different intra or intermolecular translocation pathways. In addition, conversion of the Pb /Tl complex into its Pb /Tl counterpart was achieved by addition of a stoichiometric amount of Hg salt as a sacrificial electron acceptor. These results further contribute to the elaboration of devices that feature redox-controlled compartmentalized double translocations.

Keywords: Thallium; Supramolecular chemistry; Porphyrinoids; Lead; Bimetallic complexes

Domains: Chemical Sciences

Stéphane Le Gac, Victoria Ndoyom, Luca Fusaro, Vincent Dorcet, Bernard Boitrel. Hg(II)-Mediated Tl(I)-to-Tl(III) Oxidation in Dynamic Pb(II)/Tl Porphyrin Complexes. Chemistry - A European Journal, 2019, 25 (3), pp.845-853. ⟨10.1002/chem.201804713⟩. ⟨hal-01937241⟩