Chemical and spectroscopic evidence for an FeV-oxo complex.
Iron(V)-oxo species have been proposed as key reactive intermediates in the catalysis of oxygen-activating enzymes and synthetic catalysts. Here, we report the synthesis of [Fe(TAML)(O)]- in nearly quantitative yield, where TAML is a macrocyclic tetraamide ligand. Mass spectrometry, Mössbauer, electron paramagnetic resonance, and x-ray absorption spectroscopies, as well as reactivity studies and density functional theory calculations show that this long-lived (hours at -60 degrees C) intermediate is a spin S = 1/2 iron(V)-oxo complex. Iron-TAML systems have proven to be efficient catalysts in the decomposition of numerous pollutants by hydrogen peroxide, and the species we characterized is a likely reactive intermediate in these reactions.
Tiago de Oliveira
Filipe
F
Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
Chanda
Arani
A
Banerjee
Deboshri
D
Shan
Xiaopeng
X
Mondal
Sujit
S
Que
Lawrence
L
Bominaar
Emile L
EL
Münck
Eckard
E
Collins
Terrence J
TJ
D002384:Catalysis; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004578:Electron Spin Resonance Spectroscopy; D058085:Iron Compounds / Q000737:chemistry*; D008024:Ligands; D047028:Macrocyclic Compounds / Q000737:chemistry*; D008968:Molecular Conformation; D010084:Oxidation-Reduction; D021241:Spectrometry, Mass, Electrospray Ionization; D015204:Spectroscopy, Mossbauer; D013057:Spectrum Analysis; D014965:X-Rays
D058085:Iron Compounds; D008024:Ligands; D047028:Macrocyclic Compounds; C517362:iron-3,3,6,6,9,9-hexamethyl-3,4,8,9-tetrahydro-1H-1,4,8,11-benzotetraazacyclotridecine-2,5,7,10(6H,11H)-tetraone