Synthesis, Structure, and Reactivity of an Iron(V) Nitride

Scepaniak, Jeremiah J.; Vogel, Carola; Khusniyarov, Marat M.; Heinemann, Frank W.; Meyer, Karsten; Smith, Jeremy M.

doi:10.1126/science.1198315

Cited by 328 publications

(297 citation statements)

References 22 publications

Supporting

Mentioning

272

Contrasting

Unclassified

Order By: Relevance

“…pentavalent Fe V ≡N complex [(PhB( t BuIm) 3 )Fe V (N)] + , which is the first example of an Fe V ≡N that could be isolated and thoroughly characterized in solution and in solid state 92 . An X-ray diffraction study revealed overall similar bond metrics to its tetravalent precursor, with the most remarkable feature being the very short Fe-N bond distance of 1.502 Å in crystals of [(PhB( t BuIm) 3 93 Table 1), showing localized valencies in the asymmetric mixed-valent complex 95 .…”

Section: Iron-nitrido Model Complexesmentioning

confidence: 99%

The biology and chemistry of high-valent iron–oxo and iron–nitrido complexes

2012

Self Cite

View full text Add to dashboard Cite

selective functionalization of unactivated c-H bonds and ammonia production are extremely important industrial processes. a range of metalloenyzmes achieve these challenging tasks in biology by activating dioxygen and dinitrogen using cheap and abundant transition metals, such as iron, copper and manganese. High-valent iron-oxo and -nitrido complexes act as active intermediates in many of these processes. the generation of well-described model compounds can provide vital insights into the mechanism of such enzymatic reactions. advances in the chemistry of model high-valent iron-oxo and -nitrido systems can be related to our understanding of the biological systems.H igh-valent oxoiron(IV) and formally oxoiron(V) species have been spectroscopically identified as active intermediates in the catalytic cycles of a number of enzymatic systems 1-10 . Haem and non-haem proteins use these reactive intermediates to couple the activation of dioxygen to the oxidation of their substrates. In most cases, an oxygen atom is inserted into an unactivated C-H bond of the substrate; for example, in hydroxylation reactions [1][2][3][4][5][6][7][8][9][10] . However, many other reactions, including halogenation, desaturation, cyclization, epoxidation and decarboxylation, are also known to involve oxoiron species 1,3 . Superoxidized iron complexes with (valence) isoelectronic imido and nitrido ligands, as well as 'surface nitrides' , have also been implicated as key intermediates in the nitrogen atom transfer reactions 11 , the biological synthesis of ammonia by the nitrogenase enzyme 12-16 and the industrial Haber-Bosch process 17 .The generation of well-described model compounds can provide vital insights into the mechanism of such enzymatic reactions. Consequently, considerable effort has been made by synthetic chemists to prepare viable models for the putative reaction intermediates in the catalytic cycles of O 2 and N 2 activating enzymes. In this review, we provide an overview of all high-valent oxoiron and nitridoiron species that have been either identified or proposed as reactive intermediates in biology. Subsequently, we summarize some of the recent advances in bioinorganic chemistry that have led to the identification and isolation of iron complexes in unusually high formal oxidation states, containing iron-oxygen or iron-nitrogen multiple bonds. The spectroscopic characterization and the reactivity studies of these model complexes provide vital insights into the mechanism that nature uses to induce the reductive cleavage of dioxygen or dinitrogen in carrying out a number of important biochemical oxidative transformations. Moreover, the comparative review of the electronic structures of the isoelectronic oxoiron and nitridoiron functionalities reveals that the Fe-N bonds are intrinsically more covalent than the Fe-O bonds.

show abstract

Section: Iron-nitrido Model Complexesmentioning

confidence: 99%

The biology and chemistry of high-valent iron–oxo and iron–nitrido complexes

2012

Self Cite

View full text Add to dashboard Cite

show abstract

“…[1,11,13] Figure 4 shows the example of the scheme in which different high-valent species have been demonstrated. Details of the scheme has been given elsewhere.…”

Section: Iron-nitrido Complexesmentioning

confidence: 99%

“…[6,10] In addition to iron oxo species, high-valent ironnitrido complexes have also been suggested to play significant role in nitrogenase enzyme reactions and industrial Haber-Bosch process. [11][12][13] Figure 2 depicts the postulated intermediates with iron-nitrogen multiple bonds. [1] At the single iron site, reduction of nitrogen may occur.…”

Section: Introductionmentioning

confidence: 99%

Ferryl and Ferrate Species: Mössbauer Spectroscopy Investigation

Sharma¹,

Zbořil²

2015

Croat. Chem. Acta

View full text Add to dashboard Cite

High-valent iron species of oxidation states +4, +5, and +6, have been involved as intermediates in enzymatic reactions, in green organic synthesis, and in purification and disinfection of water. Many of these species have been synthesized to understand their role in different systems, which include ferryl complexes (oxoiron(IV) (Fe IV =O), oxoiron(V) (Fe V =O)), iron(IV / V / VI)-nitride complexes, and ferrates ((Fe VI O4 2-, Fe(VI), Fe V O4 3-, Fe(V), and Fe IV O4 4-, Fe(IV)). Ferryl and iron-nitride complexes have organic ligands surrounded at the iron center and are soluble in non-aqueous solvent. Comparatively, ferrate species are tetraoxyanions and are soluble in water. This paper presents Mössbauer spectroscopy as a tool to distinguish different oxidation states of iron and to gain information on the geometry and structure of high-valent iron complexes. Examples are given to demonstrate the application of Mössbauer spectroscopy in learning mechanisms of thermal decomposition of ferrates, encapsulation of heavy metals by ferrates, and oxidation of thiols by ferrates.

show abstract

“…16−18 A tris(carbine)amine-iron(IV)-nitride was recently employed as an electrochemical precursor for a complementary iron(V) species that was stable enough for its electronic and molecular structure to be examined by crystallography and various types of spectroscopy. 19,20 Quite in contrast, iron nitrides with a fourfold symmetrical coordination geometry at the metal center are highly unstable under ambient conditions. The existence of square pyramidal and pseudo-octahedral nitrido-iron species under cryogenic conditions has been deduced from early resonance Raman spectra 21 or from a detailed spectral analysis of their decomposition products.…”

Section: ■ Introductionmentioning

confidence: 99%

The Photochemical Route to Octahedral Iron(V). Primary Processes and Quantum Yields from Ultrafast Mid-Infrared Spectroscopy

et al. 2014

View full text Add to dashboard Cite

Recently, the complex cation [(cyclam-ac)Fe III (N 3 )] + has been used in solid matrices under cryogenic conditions as a photochemical precursor for an octahedral iron nitride containing the metal at the remarkably high oxidation state +5. Here, we study the photochemical primary events of this complex cation in liquid solution at room temperature using femtosecond time-resolved mid-infrared (fs-MIR) spectroscopy as well as step-scan Fourier-transform infrared spectroscopy, both of which were carried out with variable-wavelength excitation. In stark contrast to the cryomatrix experiments, a photooxidized product cannot be detected in liquid solution when the complex is excited through its putative LMCT band in the visible region. Instead, only a redox-neutral dissociation of azide anions is seen under these conditions. However, clear evidence is found for the formation of the highly oxidized iron nitride product when the photolysis is carried out in liquid solution with UV light. Yet, the photooxidation must compete with photoreductive Fe−N bond cleavage leading to azide radicals and an iron(II) complex. Both, redox-neutral and photoreductive Fe−N bond breakage as well as photooxidative N−N bond breakage occur on a time scale well below a few hundred femtoseconds. The majority of fragments suffer from geminate recombination back to the parent complex on a time scale of 10 ps. Upper limits of the primary quantum yield for photooxidation are derived from the fs-MIR data, which increase with increasing energy of the photolysis photon.

show abstract

Synthesis, Structure, and Reactivity of an Iron(V) Nitride

Cited by 328 publications

References 22 publications

The biology and chemistry of high-valent iron–oxo and iron–nitrido complexes

The biology and chemistry of high-valent iron–oxo and iron–nitrido complexes

Ferryl and Ferrate Species: Mössbauer Spectroscopy Investigation

The Photochemical Route to Octahedral Iron(V). Primary Processes and Quantum Yields from Ultrafast Mid-Infrared Spectroscopy

Contact Info

Product

Resources

About