76282-27-4

Upstream product

• 10544-73-7 dinitrogen trioxide 
• 10544-72-6 dinitrogen tetraoxide 
• 10102-43-9 nitrogen(II) oxide 
• 16591-56-3 5,10,15,20-tetraphenyl porphyrin iron 
• 10102-44-0 Nitrogen dioxide 
• 16456-81-8 meso-tetraphenylporphyrin iron(III) chloride 
• 935699-70-0 meso-tetraphenylporphyrinato(η1-nitrito)iron(III) 

Downstream Products

• 84152-32-9 Fe(IV)=O(tetraphenylporphinate) 
• 16591-56-3 5,10,15,20-tetraphenyl porphyrin iron 
• 1006688-55-6 Fe(III)(meso-tetraphenylporphyrinato)(η1-ONO2)(THF) 
• 102494-81-5 Fe((C₆H₅)4C₂₀H₈N₄)(NO₂)2^(1-) 

Relevant academic research and scientific papers

Reactions of nitrogen oxides with heme models. Low temperature spectral characterization of the unstable nitrato-nitrosyl complex FeIII(TPP) (ONO2)(NO)

Reaction of NO gas with low temperature films of the η2-nitrato model heme FeIII(TPP)(O2NO) (TPP = mesotetraphenylporphyrinato2-) leads to formation of the previously unknown η1-nitrato nitrosyl speci

Six-coordinate nitrato complexes of iron(III) porphyrins

The interaction of tetrahydrofuran (THF) with thin films of the nitrato complexes FeIII(Por)(η2-O2NO) [Por = meso-tetraphenylporphyrinato (TPP) and meso-tetratolylporphyrinato (TTP) dianion] at low temperature leads to the formation of the six-coordinate nitrato complex Fe(Por)(THF)(NO3), which was characterized by IR and UV-visible spectroscopies. Formation of the THF adduct was accompanied by nitrate linkage isomerization from bidentate to monodentate coordination. The iron(III) center remains in a high spin state in contrast with the previously observed low-spin nitratonitrosyl complex Fe(TPP)(NO)(η1-ONO 2). Upon warming, THF dissociates to restore the initial five-coordinate bidentate nitrato complex.

Reactions of nitrogen oxides with the five-coordinate Fe III(porphyrin) nitrito intermediate Fe(Por)(ONO) in sublimed solids

Detailed experimental studies are described for reactions of several nitrogen oxides with iron porphyrin models for heme/NxOy systems. It is shown by FTIR and optical spectroscopy and by isotope labeling experiments that reaction of small increments of NO2 with sublimed thin layers of the iron(II) complex Fe(Por) (For = meso-tetraphenylporphyrinato dianion, TPP, or meso-tetra-p-tolylporphyrinato dianion, TTP) leads to formation of the 5-coordinate nitrito complexes Fe(Por)(η1-ONO) (1), which are fairly stable but very slowly decompose under vacuum giving mostly the corresponding nitrosyl complexes Fe(Por)(NO). Further reaction of 1 with new NO2 increments leads to formation of the nitrato complex Fe(Por)(η2-O2NO) (2). The interaction of NO with 1 at low temperature involves ligand addition to give the nitrito-nitrosyl complexes Fe(Por)(η1-ONO)(NO) (3); however, these isomerize to the nitro-nitrosyl analogs Fe(Por)(η1-NO2)(NO) (4) upon warming. Experiments with labeled nitrogen oxides argue for an intramolecular isomerization ( flipping ) mechanism rather than one involving dissociation and rebinding of NO2. The Fe(III) centers in the 6-coordinate species 3 and 4 are low spin in contrast to 1, which appears to be high-spin, although DFT computations of the porphinato models Fe(P)(nitrite) suggest that the doublet nitro species and the quartet and sextet nitrito complexes are all relatively close in energy. The nitro-nitrosyl complex 4 is stable under an NO atmosphere but decomposes under intense pumping to give a mixture of the ferrous nitrosyl complex Fe(Por)(NO) and the ferric nitrito complex Fe(Por)(η1-ONO) indicating the competitive dissociation of NO and NO2. Hence, loss of NO from 4 is accompanied with nitro → nitrito isomerization consistent with 1 being the more stable of the 5-coordinate NO2 complexes of iron porphyrins.

Structural and physical characterization of (nitrato)iron(III) porphyrinates [Fe(por)(NO3)] - Variable coordination of nitrate

We report the X-ray crystal structures of two different iron(III) porphyrinates: [Fe(OEP)(NO3)] and [Fe(TPP)(NO3)]. The first complex has the nitrate ion coordinated by a single oxygen atom while the second derivative has the nitrate coordinated in a symmetric bidentate fashion. This latter structure is a redetermination that shows some differences from an earlier structure; the difference appears to be the result of an unrecognized nitrate ion disorder in the earlier structure determination. Changes in physical properties of three species [Fe(TPivP)(NO3)], [Fe(OEP)(NO3)], and [Fe-(TPP)-(NO3)] as a function of coordination mode were examined by M?ssbauer and EPR spectroscopies; EPR spectra appear to be most sensitive to the change in coordination mode.

Reactions of nitrogen oxides with heme models: Spectral characterization of an elusive five-coordinate FeIII(porphyrin) nitrito intermediate

(Chemical Equation Presented) The famous five: The elusive five-coordinate nitrito complexes [FeIII(por)(ONO)] (por = meso- tetraphenylporphyrinato dianion or meso-tetra-p-tolylporphyrinato dianion) have been obtained by interaction of low-pres

Reactions of nitrogen oxides with heme models. Spectral and kinetic study of nitric oxide reactions with solid and solute FeIII(TPP)(NO 3)

The reaction(s) of nitric oxide (nitrogen monoxide) gas with sublimed layers containing the nitrato iron(III) complex FeIII(TPP) (η2-O2NO) (1, TPP = meso-tetraphenyl porphyrinate 2-) leads to formation of several iron porphyrin species that are ligated by various nitrogen oxides. The eventual products of these low-temperature solid-state reactions are the nitrosyl complex Fe(TPP)(NO), the nitro-nitrosyl complex Fe(TPP)(NO2)(NO), and 1 itself, and the relative final quantities of these were functions of the NO partial pressure. It is particularly notable that isotope labeling experiments show that the nitrato product is not simply unreacted 1 but is the result of a series of transformations taking place in the layered material. Thus, the nitrato complex formed from solid Fe(TPP)(η2-O2NO) maintained under a 15NO atmosphere was found to be the labeled analogue Fe(TPP)(η2-O215NO). The reactivities of the layered solids are compared to the behaviors of the same species in ambient temperature solutions. To interpret the reactions of the labeled nitrogen oxides, the potential exchange reactions between N2O3 and 15NO were examined, and complete isotope scrambling was observed between these species under the reaction conditions (T = 140 K). Overall it was concluded from isotope labeling experiments that the sequence of reactions is initiated by reaction of 1 with NO to give the nitrato nitrosyl complex Fe(TPP)(η1-ONO2)(NO) (2) as an intermediate. This is followed by a reaction in the presence of excess NO that is equivalent to the loss of the nitrate radical NO3. to give Fe(TPP)(NO) as another transient species. A plausible pathway involving NO attack on the coordinated nitrate of 2 resulting in the release of N2O4 concerted with electron transfer to the metal center is proposed.

Reactions of nitrogen oxides with heme models. Characterization of NO and NO2 dissociation from Fe(TPP)(NO2)(NO) by flash photolysis and rapid dilution techniques: Fe(TPP)(NO2) as an unstable intermediate

Described are studies directed toward elucidating the controversial chemistry relating to the solution phase reactions of nitric oxide with the iron(II) porphyrin complex Fe(TPP)(NO) (1, TPP = mesotetraphenylporphinato2-). The only reaction observable with clean NO is the formation of the diamagnetic dinitrosyl species Fe(TPP)(NO)2 (2), and this is seen only at low temperatures (K1 -1 at ambient temperature). However, 1 does readily react reversibly with N2O3 in the presence of excess NO to give the nitro nitrosyl complex Fe(TPP)(NO2)(NO) (3), suggesting that previous claims that 1 promotes NO disproportionation to give 3 may have been compromised by traces of air in the nitric oxide sources. It is also noted that 3 undergoes reversible loss of NO to give the elusive nitro species Fe(TPP)(NO2) (4), which has been implicated as a powerful oxygen atom transfer agent in reactions with various substrates. Furthermore, in the presence of excess NO2, the latter undergoes oxidation to the stable nitrato analogue Fe(TPP)(NO3) (5). Owing to such reactivity of Fe(TPP)(NO2), flash photolysis and stopped-flow kinetics rather than static techniques were necessary for the accurate measurement of dissociation equilibria characteristic of Fe(TPP)(NO2)(NO) in 298 K toluene solution. Flash photolysis of 3 resulted in competitive NO2 and NO dissociation to give Fe(TPP)(NO) and Fe(TPP)(NO2), respectively. The rate constant for the reaction of 1 with N2O3to generate Fe(TPP)(NO2)(NO) was determined to be 1.8 × 106 M-1 s-1, and that for the NO reaction with 4 was similarly determined to be 4.2 × 105 M-1 s-1. Stopped-flow rapid dilution techniques were used to determine the rate constant for NO dissociation from 3 as 2.6 s-1. The rapid dilution experiments also demonstrated that Fe(TPP)(NO2) readily undergoes further oxidation to give Fe-(TPP)(NO3). The mechanistic implications of these observations are discussed, and it is suggested that NO2 liberated spontaneously from Fe(P)(NO2) may play a role in an important oxidative process involving this elusive species.

Spectroscopic study of the interaction between nitrogen dioxide and sublimed layers of iron(II) mesotetraphenylporphyrin

IR and electronic absorption spectroscopies with the use of isotopically substituted 15NO2 have shown that the reaction of nitrogen dioxide with sublimed layers of iron(II) mesotetraphenylporphyrin (FeTPP) has complex character and yields nitrato complex FeIIITPP · NO3-. The spectroscopic data obtained suggest that the initial stages of reaction results in structures in which NO2 is coordinated to FeTPP through the oxygen atom. Treatment of the sublimed FeTPP layers with a mixture of nitrogen oxide and dioxide result in the formation of the nitrosyl (FeTPP · NO) and nitro-nitrosyl (O2N · FeTPP · NO) complexes in the sublimed layer.

Reaction of certain nitrogen oxides with iron(III) porphyrin μ-oxo complexes

The nitrogen oxides NO, N2O4, and N2O3 and the μ-oxo complexes [Fe(TPP)]2O and [Fe(OEP)]2O, where TPP and OEP are the dianions of meso-tetraphenylporphine and octaethylporphyrin, respectively, were reacted in toluene in the absence of O2. [Fe(TPP)]2O was reacted with the nitrogen oxides in dimethylacetamide (DMA). All of the reactions were followed by changes in the electronic spectra. The NO reaction with [Fe(TPP)]2O in toluene yielded a solid product, Fe(TPP)(NO)(NO2)·C7H8·2H 2O. The N2O4 and the N2O3 reactions in toluene produced Fe(TPP)NO3 and Fe(OEP)NO3, while in DMA these reactions gave an equilibrium amount of Fe(TPP)(DMA)x+, the solvated complex.

Solid-state and solution properties of (N,N′-ethylenebis(salicylideneaminato))(nitrato)iron(III) and related complexes

Two solid-state forms of the title complex, Fe(salen)NO3, were prepared by reacting a methylene chloride solution of [Fe(salen)]2O with aqueous 0.5 M nitric acid and precipitating the complex either with ether or with pentane. The form isolated from pentane was dimeric with a unidentate nitrate bound to each iron, [Fe(salen)ONO2]2, while the other form was monomeric with a bidentate nitrate, Fe(salen)O2NO. The reaction was carried out with three other salicylideneamine iron(III) μ-oxo complexes, and only the dimeric, unidentate nitrate form of each was prepared. The 15N-labeled nitrate complexes were used to assign the nitrate infrared bands. The 57Fe Mo?ssbauer spectra and magnetic susceptibilities of the complexes were compared to similar data for the tetraphenylporphyrin complex Fe(TPP)O2NO, which is monomeric with a bidentate nitrate. The proton NMR spectra of the two forms of Fe(salen)NO3 in solution were identical, as were the solution infrared spectra, and such spectra indicated that the solution species were monomeric with bidentate nitrate ligands.