Water as an Oxygen Source in the Generation of Mononuclear Nonheme Iron(IV) Oxo Complexes

Abstract

Give me an "O"! Mononuclear nonheme iron(IV) oxo complexes have been generated using water as an oxygen source and cerium(IV) as an oxidant. The high-yield oxygenation of organic substrates in this system (see picture, Fe green, O red, N blue, C gray) is catalyzed by iron(II) complexes. The source of oxygen in the iron(IV) oxo complexes and the oxygenated products has been assigned unambiguously by isotopic labeling experiments.

Identification and Spectroscopic Characterization of Nonheme Iron(III) Hypochlorite Intermediates

“…The absorbance at 670 nm is attributed to an Fe IV =O complex. This assignment was confirmed by comparison of electrospray ionization mass spectrometry (ESIMS), 1 H NMR (Figure S8) and resonance Raman (rR) spectroscopy (Fe IV =O; ν s =843 cm −1 ),[15] and other data with an independently prepared sample of [Fe IV (O)(MeN4Py)] 2+ . The formation of the Fe IV =O species, furthermore, is consistent with the earlier observations by Banse and co-workers of the reaction of related Fe II complexes with NaOCl.…”

Homo‐ and Heterovalent Polynuclear Cerium and Cerium/Manganese Aggregates

“…In biomimetic studies, the formation of high-oxidation-state Ru oxo complexes has been well established for H 2 O oxidation in the presence of a strong oxidant such as Ce IV or [Ru(bpy) 3 ] 3þ [19]. Recently, Fukuzumi, Nam, and co-workers employed Ce IV as a oneelectron oxidant in the generation of mononuclear non-heme Fe IV oxo complexes and in the catalytic oxidation of organic substrates with H 2 O as an O-atom source [20]. Despite these properties of Mn IV and Ce IV compounds, it is rather surprising that there are still rather few reports of Ce IV -containing heterometallic complexes [9].…”

Oxidation of Naphthalene with a Manganese(IV) Bis(hydroxo) Complex in the Presence of Acid

“…The latter method is inspired by the similar synthetic strategy of Nam and coworkers reported previously. [26,27] The ESI-MS of 2 exhibits a prominent peak at m / z = 220.7 (Figure 2b), whose mass and isotope distribution pattern correspond to [Mn IV (TBDAP)(OH) 2 ] 2+ ( 2 - 16 O) (calculated m / z = 220.6). Upon substitution of PhI 16 O with PhI 18 O, a mass peak corresponding to [Mn IV (TBDAP)( 18 OH) 2 ] 2+ ( 2 - 18 O) is obtained at m /z = 222.7 (calculated m/z = 222.6) (Figure 2b, inset), demonstrating 2 contains two oxygen atoms.…”