title: Electron Transfer to a Phosphomolybdate Monolayer on Glassy Carbon: Ambivalent Effect of Protonation.
abstract: The polyoxomolybdate hybrid TBA3[PMo11O39{Sn(C6H4)C≡C(C6H4)N2}] K(Mo)Sn[N2(+)] was prepared through Sonogashira-type coupling between TBA4[PMo11O39{Sn(C6H4)I}] K(Mo)Sn[I] and an excess of 3,3-diethyl-1-(4-ethynylphenyl)triaz-1-ene bearing a protected diazonium function, followed by its deprotection by the addition of trifluoroacetic acid (TFA). This enlarges the family of organic-inorganic polyoxomolybdate-based hybrids, which has been far less investigated than their related polyoxotungstates. The diazonium function allows for the electrochemical grafting on glassy carbon, and the K(Mo)Sn-modified electrode was further probed by cyclic voltammetry. The PMo11Sn core was found to be highly sensitive to protonation, and five bielectronic proton-coupled electron transfer processes were detected in the presence of an excess of TFA, thus corresponding to the injection of up to 10 electrons in the potential range between 0.15 and -0.45 V/SCE. The gain observed in the thermodynamic potentials is however detrimental to the apparent kinetics of the electron transfer, which drops from 500 s(-1) in the absence of acid to 12 s(-1) in the presence of an excess of TFA.
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 8232, Institut Parisien de Chimie Moléculaire, Université Pierre et Marie Curie, 4 Place Jussieu, F-75005 Paris, France.
authors.forename: Corentin
authors.initials: C
authors.lastname: Rinfray
authors.affiliation: Sorbonne Paris Cité, Univ Paris Diderot, CNRS, UMR 7086, ITODYS, 15 Rue J. A. Baif, F-75013 Paris, France.
authors.forename: Vitor
authors.initials: V
authors.lastname: Brasiliense
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 8232, Institut Parisien de Chimie Moléculaire, Université Pierre et Marie Curie, 4 Place Jussieu, F-75005 Paris, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Izzet
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 8232, Institut Parisien de Chimie Moléculaire, Université Pierre et Marie Curie, 4 Place Jussieu, F-75005 Paris, France.
authors.forename: Florence
authors.initials: F
authors.lastname: Volatron
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 8232, Institut Parisien de Chimie Moléculaire, Université Pierre et Marie Curie, 4 Place Jussieu, F-75005 Paris, France.
authors.forename: Sandra
authors.initials: S
authors.lastname: Alves
authors.affiliation: Sorbonne Paris Cité, Univ Paris Diderot, CNRS, UMR 7086, ITODYS, 15 Rue J. A. Baif, F-75013 Paris, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Combellas
authors.affiliation: Sorbonne Paris Cité, Univ Paris Diderot, CNRS, UMR 7086, ITODYS, 15 Rue J. A. Baif, F-75013 Paris, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Kanoufi
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, CNRS, UMR 8232, Institut Parisien de Chimie Moléculaire, Université Pierre et Marie Curie, 4 Place Jussieu, F-75005 Paris, France.
authors.forename: Anna
authors.initials: A
authors.lastname: Proust