title: Observation of Fe(V)=O using variable-temperature mass spectrometry and its enzyme-like C-H and C=C oxidation reactions.
abstract: Oxo-transfer chemistry mediated by iron underpins many biological processes and today is emerging as synthetically very important for the catalytic oxidation of C-H and C=C moieties that are hard to activate conventionally. Despite the vast amount of research in this area, experimental characterization of the reactive species under catalytic conditions is very limited, although a Fe(V)=O moiety was postulated. Here we show, using variable-temperature mass spectrometry, the generation of a Fe(V)=O species within a synthetic non-haem complex at -40 °C and its reaction with an olefin. Also, with isotopic labelling we were able both to follow oxygen-atom transfer from H(2)O(2)/H(2)O through Fe(V)=O to the products and to probe the reactivity as a function of temperature. This study pioneers the implementation of variable-temperature mass spectrometry to investigate reactive intermediates.
authors.affiliation: Departament de Química, Universitat de Girona, Campus de Montilivi, Girona 17071, Spain.
authors.forename: Irene
authors.initials: I
authors.lastname: Prat
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Mathieson
authors.forename: Mireia
authors.initials: M
authors.lastname: Güell
authors.forename: Xavi
authors.initials: X
authors.lastname: Ribas
authors.forename: Josep M
authors.initials: JM
authors.lastname: Luis
authors.forename: Leroy
authors.initials: L
authors.lastname: Cronin
authors.forename: Miquel
authors.initials: M
authors.lastname: Costas
mesh_terms: D000475:Alkenes / Q000737:chemistry; D002244:Carbon / Q000737:chemistry; D002384:Catalysis; D006859:Hydrogen / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D007501:Iron / Q000737:chemistry*; D007553:Isotope Labeling; D013058:Mass Spectrometry; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D013696:Temperature; D013816:Thermodynamics
chemical_list: D000475:Alkenes; D010087:Oxides; C066318:perferryl iron; D002244:Carbon; D006859:Hydrogen; D006861:Hydrogen Peroxide; D007501:Iron