12582-61-5Relevant articles and documents
Structure of the deoxymyoglobin model [Fe(TPP)(2-MeHIm)] reveals unusual porphyrin core distortions
Ellison, Mary K.,Schulz, Charles E.,Scheidt, W. Robert
, p. 2173 - 2181 (2002)
The preparation and characterization of the deoxymyoglobin model (2-methylimidazole)(tetraphenylporphinato)iron-(II) is described. The preparation and crystallization from chlorobenzene leads to a new crystalline phase that has been structurally character
Syntheses of ferrous-porphyrin complexes. A hypothetical model for deoxymyoglobin.
Collman,Reed
, p. 2048 - 2049 (1973)
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Dioxygen Insertion into Iron(III)-Carbon Bonds. NMR Studies of the Formation and Reactivity of Alkylperoxo Complexes of Iron(III) Porphyrins
Arasasingham, Ramesh D.,Balch, Alan L.,Cornman, Charles R.,Latos-Grazynski, Lechoslaw
, p. 4357 - 4363 (1989)
The behavior of PFeIIICHR2 (P is a porphyrin dianion) in solution especially in the presence of dioxygen has been examined by (1)H and (2)H NMR measurements.Evidence for the photolytic Fe-C bond homolysis with the formation of PFeII is presented.Addition of dioxygen to PFeCH2R produces two unstable intermediates, PFeIIIO2CH2R and PFeIIIOH, which may be directly observed at low temperatures.These form and decompose through the following reactions: PFeIIICH2R + O2 -> PFeIIIO2CHR2; PFeIIIO2CHR2 -> PFeIIIOH + O=CR2; 2PFeIIIOH -> PFeIIIOFeIIIP + H2O.The formation of the product aldehyde or ketone has been established for methyl, ethyl, isopropyl, n-propyl, and benzyl ligands axially coordinating iron.The dioxygen insertion is retarded by the coordination of N-methylimidazole to the sixth iron coordination site or by employing a sterically encumbered porphyrin.PFeIIIOH catalyzes the decomposition of ethyl hydroperoxide to give acetaldehyde as the major organic product.
Newman, Alan R.,French, Andrew N.
, p. L37 - L40 (1987)
Comparison of Variable-Temperature 1H NMR Spectra of Five-Coordinate High-Spin (S=5/2) Iron(III) Porphyrins and Chlorins
Pawlik, M. J.,Miller, P. K.,Sullivan, E. P.,Levstik, M. A.,Almond, D. A.,Strauss, S. H.
, p. 3007 - 3012 (1988)
Variable-temperature 1H NMR spectra are reported for five different five-coordinate high-spin (S=5/2) iron(III) chlorin complexes.The complexes are Fe(TPC)X (X-=Cl-, OTeF5-) and Fe(OEC)X (X-=Cl-, OTeF5-, NCS-), where TPC=tetraphenylchlorinate dianion and OEC=octaethylchlorinate dianion.For completeness, variable-temperature spectra are also reported for the five homologous porphyrin complexes, although with one exception, Fe(OEP)(NCS), these porphyrin data have been reported by others.Spectra and Curie plots for the two classes of complexes are compared and spectral characteristics that are unique to chlorins are discussed.Our data show that the various types of pyrrole protons in the TPCcomplexes and the various types of pyrrole methylene protons in the OEC complexes exhibit a large range of isotropic shifts, ca. 30 ppm at ca. 300 K.The average temperature dependence of the resonances (i.e., Curie plot slopes) is similar to the temperature dependence of the resonance(s) for porphyrin protons in chemically similar positions.For both sets of chlorin complexes, pyrroline proton or methylene proton isotropic shifts are substantially smaller than pyrrole isotropic shifts, while pyrroline proton or methylene proton line widths are larger than pyrrole proton line widths.Large deviations in Curie plot 1/T=0 intercepts from diamagnetic chemical shifts are observed for many of the chlorin proton resonances.This behavior has been observed for all paramagnetic iron(II,III) hydroporphyrins studied to date.The different axial ligands greatly influence the range of isotropic shifts for the pyrrole protons or pyrrole methylene protons for a given chlorin and the temperature dependence (Curie plot slopes and intercepts) of the pyrroline protons for the TPC complexes.
Synthesis and Magnetic Exchange Properties of Linear Trinuclear Oxo- Bridged M(III)ORu(IV)OM(III) Complexes (M = Fe, Cr, Mn) Formed by Two-Electron Redox Reactions
Berry, Kevin J.,Moubaraki, Boujemaa,Murray, Keith S.,Nichols, Peter J.,Schulz, Lewis D.,West, Bruce O.
, p. 4123 - 4133 (1995)
The two-electron reductions of various porphyrin complexes Ru(VI)(O)2(P) by Fe(II), Cr(II), and Mn(II) compounds of porphyrins and salicylaldimines result in the formation of heterotrimetallic oxo-bridged complexes (L)M(III)ORu(IV)(P)OM(III)(L) (M = Fe(III), Cr(III), Mn(III); P is the dianion of 5,10,15,20-tetraarylporphyrins, such as tetraphenylporphyrin (TPP), tetrakis(p-methoxyphenyl)porphyrin (TMP), or 2,3,7,8,12,13,17,18-octaethylporphyrin (OEP); L is TPP, TMP, or OEP or the dianions of N,N'-(4-methyl-4-azaheptane-1,7-diyl)bis(salicylaldimine) (salmah) or N,N'-ethane-1,2-diylbis(salicylaldimine) (salen). A detailed study of the temperature- and field-dependent magnetic properties of this rather novel series of (L)M(III)ORu(IV)(P)OM(III)(L) compounds has been made. The spin-states of the constituent metal centers are as follows: Ru(IV), SRu = 1 (d(4)); Fe(III), SFe = 5/2 (d(5)); Cr(III), SCr = 3/2 (d(3)); Mn(III), SMn= 4/2 (d(4)). The spin-state and coordination geometry of the (L)Fe(III) groups were confirmed by Moessbauer spectral measurements. Trinuclear combinations of the present kind give rise to unusual coupled spin-stateenergy levels which, in the case of (L)Fe(III)ORu(IV)(P)OFe(III)(L) compounds, result in "ferromagnetic-like" plots of magnetic moment versus temperature, particularly at low temperatures. The following best-fit values of parameters were deduced from the magnetic moment data, obtained in 1 T fields over the temperature range 4.2-300 K. (salmah)FeORu(TPP)OFe(salmah): g = 1.97, J12 = -19.7 cm**-1, J13 = +6.5 cm**-1, α = J13/J12 = -0.33, ground-state S = 4; (TMP)FeORu(TPP)OFe(TMP): g = 1.95, J12= -23.4 cm**-1, J13 = 5.4 cm**- 1, α = -0.23, ground-state S = 4.(TPP)FeORu(TPP)OFe(TPP): g = 2.0, J12 = -35.7 cm**-1, J13 = 11.2 cm**-1, α = -0.31, ground-state S = 4, [(TPP)Fe]2O impurity = 13%, zero-field splitting of the S = 4 state (D ~ 5 cm**-1). (TMP)MnORu(TPP)OMn(TMP): g = 1.93, J12 = -17.4 cm**-1, J13 = 9.6 cm**-1, α = -0.55, ground-state S = 3. (TPP)CrORu(TPP)OCr(TPP): g = 1.98, J12 = -25.3 cm**-1, J13 = -11.1 cm**-1, α = 0.44, ground-state S = 1. Possiblereasons for the small sizes of the J12 values, in comparison to those of related M(III)OM(III) and Ru(IV)ORu(IV) compounds, are discussed.
Meso-Tetraphenylporphyrin Iron Chloride Catalyzed Selective Oxidative Cross-Coupling of Phenols
Shalit, Hadas,Libman, Anna,Pappo, Doron
supporting information, p. 13404 - 13413 (2017/10/05)
A novel catalytic system for oxidative cross-coupling of readily oxidized phenols with poor nucleophilic phenolic partners based on an iron meso-tetraphenylporphyrin chloride (Fe[TPP]Cl) complex in 1,1,1,3,3,3-hexafluoropropan-2-ol (HFIP) was developed. The unique chemoselectivity of this reaction is attributed to the coupling between a liberated phenoxyl radical with an iron-ligated phenolic coupling partner. The conditions are scalable for preparing a long list of unsymmetrical biphenols assembled from a less reactive phenolic unit substituted with alkyl or halide groups.
Five- and six-coordinate adducts of nitrosamines with ferric porphyrins: Structural models for the type II interactions of nitrosamines with ferric cytochrome P450
Xu, Nan,Goodrich, Lauren E.,Lehnert, Nicolai,Powell, Douglas R.,Richter-Addo, George B.
, p. 4405 - 4419 (2010/07/04)
Nitrosamines are well-known for their toxic and carcinogenic properties. The metabolic activation of nitrosamines occurs via interaction with the heme-containing cytochrome P450 enzymes. We report the preparation and structural characterization of a number of nitrosamine adducts of synthetic iron porphyrins. The reactions of the cations [(por)Fe(THF)2]ClO 4 (por = TPP, TTP, OEP) with dialkylnitrosamines (R2NNO; R2 = Me2, Et2, (cyclo-CH2) 4, (cyclo-CH2)5, (PhCH2) 2) in toluene generate the six-coordinate high-spin (S = 5/2) [(por)Fe(ONNR2)2]ClO4 compounds and a five-coordinate intermediate-spin (S = 3/2) [(OEP)Fe(ONNMe2)]ClO 4 derivative in 57-72% yields (TPP = 5,10,15,20- tetraphenylporphyrinato dianion, TTP = 5,10,15,20-tetra-p-tolylporphyrinato dianion, OEP = 2,3,7,8,12,13,17,18-octaethylporphyrinato dianion). The N-O and N-N vibrations of the coordinated nitrosamine groups in [(por)Fe(ONNR 2)2]ClO4 occur in the 1239-1271 cm-1 range. Three of the six-coordinate [(por)Fe(ONNR2) 2]ClO4 compounds and one five-coordinate [(OEP)Fe(ONNMe2)]ClO4 compound have been characterized by single crystal X-ray crystallography. All the nitrosamine ligands in these complexes bind to the ferric centers via a sole η1-O binding mode. No arylnitrosamine adducts were obtained from the reactions of the precursor compounds [(por)Fe(THF)2]ClO4 with three arylnitrosamines (Ph2NNO, Ph(Me)NNO, Ph(Et)NNO). However, prolonged exposure of [(por)Fe(THF)2]ClO4 to these arylnitrosamines resulted in the formation of the known five-coordinate (por)Fe(NO) derivatives. The latter (por)Fe(NO) compounds were obtained more readily by the reactions of the three arylnitrosamines with the four-coordinate (por)FeII precursors.
Heme carbonyls: Environmental effects on vc-o and Fe-C/C-O bond length correlations
Silvernail, Nathan J.,Roth, Arne,Schulz, Charles E.,Noll, Bruce C.,Scheldt, W. Robert
, p. 14422 - 14433 (2007/10/03)
The synthesis and characterization of four low-spin (carbonyl)iron(11) tetraphenylporphyrinates, [Fe(TPP)(CO)(L)], where L = 1-methylimidazole, 2-methylimidazole, 1,2-dimethylimidazole (unsolvated), and 1,2-dimethylimidazole (toluene solvate) are reported. The complexes show nearly the same value of vc-o in toluene solution (1969-72 cm-1) but a large range of CO stretching frequencies in the solid-state (1926-1968 cm-1). The large solid-state variation results from CO interactions in the solid state, as shown by an examination of the crystal structures of the four complexes. The high precision of the four structures obtained allows us to make a number of structural and spectroscopic correlations that describe the Fe-C-O and N lm-Fe-CO units. The values of vc-o and the Fe-C and C-O bond distances are strongly correlated and provide a structural, as well as a spectroscopic, correlation of the π back-bonding model. The interactions of CO described are closely related to the large range of CO stretching frequencies observed in heme proteins and specific interactions observed in carbonylmyoglobin (MbCO).
