title: Hydroxide ion versus chloride and methoxide as an exogenous ligand reveals the influence of hydrogen bonding with second-sphere coordination water molecules in the electron transfer kinetics of Mn complexes.
abstract: We recently reported on the synthesis of a new pentadentate N(4)O ligand, tBuL(-), together with the X-ray diffraction structure of the corresponding mononuclear manganese(III)-hydroxo complex namely [(tBuL)Mn(III)OH](ClO(4)), (1 (ClO(4))). [El Ghachtouli et al. Energy Environ. Sci. 2011, 4, 2041.] In the present work, we evidence through electrochemical analysis that complex 1(+), in the presence of water, shows a peculiar behavior toward electron-transfer kinetics. The synthesis, single-crystal X-ray diffraction, and EPR spectroscopic characterization of two other mononuclear manganese(III)-chlorido and methoxo complexes-namely, [(tBuL)Mn(III)Cl](PF(6)), (2(PF(6))) and [(tBuL)Mn(III)OMe](ClO(4)), (3(ClO(4)))-are also reported. 2(PF(6)) and 3(ClO(4)) compounds will serve as reference complexes for the electron-transfer kinetics investigation. The peculiar behavior of 1(ClO(4)) is attributed to the specificity of hydroxide anion as ligand presumably allowing intermolecular hydrogen-bonding interactions and thus affecting electron-transfer properties.
authors.affiliation: Laboratoire d'Electrochimie Moléculaire, Univ Paris Diderot, Sorbonne Paris Cité, Unité Mixte de Recherche Université-CNRS No. 7591, Bâtiment Lavoisier, 15 rue Jean de Baïf, 75205 Paris Cedex 13, France.
authors.forename: Sanae
authors.initials: S
authors.lastname: El Ghachtouli
authors.forename: Régis
authors.initials: R
authors.lastname: Guillot
authors.forename: Ally
authors.initials: A
authors.lastname: Aukauloo
authors.forename: Pierre
authors.initials: P
authors.lastname: Dorlet
authors.forename: Elodie
authors.initials: E
authors.lastname: Anxolabéhère-Mallart
authors.forename: Cyrille
authors.initials: C
authors.lastname: Costentin
mesh_terms: D002712:Chlorides / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004563:Electrochemistry; D004583:Electrons; D006860:Hydrogen Bonding; D006878:Hydroxides / Q000737:chemistry*; D007700:Kinetics; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D021241:Spectrometry, Mass, Electrospray Ionization; D013056:Spectrophotometry, Ultraviolet
chemical_list: D002712:Chlorides; D006878:Hydroxides; D008024:Ligands