title: Capture of the complex [Ni(dto)2]2- (dto2- = dithiooxalato ligand) in a Mo12 ring: synthesis, characterizations, and application toward the reduction of protons.
abstract: The encapsulation of the complex [Ni(dto)(2)](2-) within an oxothiododecamolybdic cyclic cluster has been investigated. The resulting molybdenum ring, [Mo(12)O(12)S(12)(OH)(12)(Ni(dto)(2))](2-), corresponds to the first example of the {Mo(2)O(2)S(2)}-based assembly arranged around a 3d transition-metal complex. It was unambiguously characterized in the solid state and in solution by FT-IR spectroscopy, single-crystal X-ray diffraction, NMR, UV-visible spectroscopy, and electrospray ionization-high-resolution mass spectrometry (ESI-HRMS). The latter technique revealed to be a powerful tool for the characterization of templated molybdenum ring systems in solution and gave excellent results in high resolution. The electronic spectrum of [Mo(12)O(12)S(12)(OH)(12)(Ni(dto)(2))](2-) evidenced a strong red shift of the LMCT bands attributed to the complex [Ni(dto)(2)](2-), suggesting significant variations of the electronic properties upon its encapsulation within the Mo(12) ring. These differences were demonstrated by electrochemical studies in CH(3)CN, which also revealed, for both compounds [Ni(dto)(2)](2-) and [Mo(12)O(12)S(12)(OH)(12)(Ni(dto)(2))](2-), electrocatalytic properties for the reduction of protons. These results evidence the ability of dithioxalato complexes to act as electrocatalysts for the hydrogen evolution reaction (HER) and confirm such a property for oxothiomolybdenum rings.
authors.affiliation: Institut Lavoisier de Versailles, UMR 8180, Université de Versailles Saint-Quentin en Yvelines, 45 avenue des Etats-Unis, 78035 Versailles, France.
authors.forename: Akram
authors.initials: A
authors.lastname: Hijazi
authors.forename: Justin Claude
authors.initials: JC
authors.lastname: Kemmegne-Mbouguen
authors.forename: Sébastien
authors.initials: S
authors.lastname: Floquet
authors.forename: Jérôme
authors.initials: J
authors.lastname: Marrot
authors.forename: Cédric R
authors.initials: CR
authors.lastname: Mayer
authors.forename: Vincent
authors.initials: V
authors.lastname: Artero
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Cadot