Mössbauer spectroscopic studies of carbonyl haemochromes; correlations with reactivity

James, Brian R.; Sams, J. R.; Tsin, Tsang Bik; Reimer, Kenneth J.

doi:10.1039/c39780000746

Cited by 20 publications

(21 citation statements)

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“…where k is the scaling factor and the n i values are the effective populations of the 3d orbitals. 74 Values of V zz are related to the measured 57 Fe quadrupole splitting constants by the expression…”

Section: Resultsmentioning

confidence: 99%

“…where e is the charge on the electron, η is the asymmetry parameter (V xx −V yy /V zz ), and Q is the quadrupole moment of the 57 Fe nucleus in its excited state. Measurements in applied magnetic field show that the asymmetry parameter γ is effectively zero for all CS complexes studied and that the sign of V zz is always positive.…”

Section: Resultsmentioning

confidence: 99%

“…4-Dimethylaminopyridine was recrystallized from toluene. 57 Fe 2 O 3 (95% enriched) was purchased from Cambridge Isotope Laboratories and used as received. Octaethylporphyrin was purchased from Midcentury Chemicals and was used as received.…”

Section: General Informationmentioning

confidence: 99%

“…The solid-state Mössbauer samples were immobilized in Apiezon M grease. Spectra were obtained for [Fe(OEP)(CS)] using iron at normal and 95% enrichment in 57 Fe while spectra for [Fe(OEP)(CS)(Py)], [Fe (OEP)(CS)(1-MeIm)], [Fe(OEP)(CS)(4-CNPy)], [Fe(OEP)(CS)(4-NMe 2 Py)] and [Fe(OEP) (CS)(Pip)], were obtained from enriched samples that had been prepared for another experiment. For the enriched iron derivatives, due to the small quantity of sample required, thin, dilute grease mulls were used to make the sample as uniform as possible.…”

Section: General Informationmentioning

confidence: 99%

“…The reaction mixture was stirred at 80°; for 12 hours to ensure complete metallation. [ 57 Fe(OEP)(CS)] was prepared by the same procedure as described above from 57 Fe(OEP)Cl. ν CS -1291 cm −1 .…”

Section: Preparation Of [ 57 Fe(oep)cl] and [ 57 Fe(oep)(cs)]mentioning

confidence: 99%

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Effect of the Sixth Axial Ligand in CS-Ligated Iron(II)octaethylporphyrinates: Structural and Mössbauer Studies

et al. 2003

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The effect of a sixth ligand in a series of low-spin thiocarbonyl-ligated iron(II)octaethylporphyrinates has been investigated. Six-coordinate complexes have been synthesized and characterized by Mössbauer and infrared spectroscopy and single-crystal X-ray structure determinations. The results are compared with the five-coordinate parent complex. The crystal structures of [Fe(OEP)(CS)(1-MeIm)] and [Fe(OEP)(CS)(Py)] are reported and discussed. The 1-methylimidazole and pyridine derivatives exhibit Fe-C(CS) bond distances of 1.703(4) and 1.706(2) A that are significantly longer than the 1.662(3) A reported for five-coordinate [Fe(OEP)(CS)] (Scheidt, W. R.; Geiger, D. K. Inorg. Chem. 1982, 21, 1208). The trans Fe-N(ligand) distances of 2.112(3) and 2.1550(15) A observed for the 1-methylimidazole and pyridine complex are approximately 0.13 A longer than those observed for analogous bis-ligated complexes and are consistent with a significant structural trans effect for the CS ligand. Mössbauer investigations carried out for five- and six-coordinate thiocarbonyl derivatives with several different sixth axial ligands reveal interesting features. All derivatives exhibit very small isomer shift values, consistent with a very strong interaction between iron and CS. The five-coordinate derivative has delta(Fe) = 0.08 mm/s, and the six-coordinate complexes exhibit delta(Fe) = 0.14 to 0.19 mm/s at 4.2 K. The five-coordinate complex shows a large quadrupole splitting (DeltaE(q) = 1.93 mm/s at 4.2 K) which is reduced on coordination of the sixth ligand (DeltaE(q) = 0.42-0.80 mm/s at 4.2 K). Addition of a sixth ligand also leads to a small decrease in the value of nu(CS). Correlations in structural, IR, and Mössbauer results suggest that the sixth ligand effect is primarily induced by changes in sigma-bonding. The structure of [Fe(OEP)(CS)(CH(3)OH)] is briefly reported. Crystal data: [Fe(OEP)(CS)(1-MeIm)] crystallizes in the monoclinic system, space group P2(1)/n, Z = 4, a = 9.5906(5) A, b = 16.704(4) A, c = 23.1417(6) A, beta = 100.453(7) degrees. [Fe(OEP)(CS)(Py)] crystallizes in the triclinic system, space group P1, Z = 5, a = 13.9073(6) A, b = 16.2624(7) A, c = 22.0709(9) A, alpha = 70.586(1) degrees, beta = 77.242(1) degrees, gamma = 77.959(1) degrees. [Fe(OEP)(CS)(CH(3)OH)] crystallizes in the triclinic system, space group P1, Z = 1, a = 9.0599(5) A, b = 9.4389(5) A, c = 11.0676(6) A, alpha = 90.261(1) degrees, beta = 100.362(1) degrees, gamma = 114.664(1) degrees.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: General Informationmentioning

confidence: 99%

Section: General Informationmentioning

confidence: 99%

Section: Preparation Of [ 57 Fe(oep)cl] and [ 57 Fe(oep)(cs)]mentioning

confidence: 99%

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Effect of the Sixth Axial Ligand in CS-Ligated Iron(II)octaethylporphyrinates: Structural and Mössbauer Studies

et al. 2003

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Mössbauer, Crystallographic, and Density Functional Theoretical Investigation of the Electronic Structure of Bis-Ligated Low-Spin Iron(II) Phthalocyanines

Nemykin

Kobayashi

Chernii

et al. 2001

Eur. J. Inorg. Chem.

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We present the crystal structure of pcFe(4‐methylpiperidine)2 as a first example of a low‐spin iron(II) phthalocyanine (pc) complex bis‐axially coordinated by aliphatic amines. It is shown that electronic rather than steric effects are responsible for the elongation of the Fe−N(axial) bond in pcFeL2 complexes. Using density functional theory, the electronic structures as well as Mössbauer isomer shifts and quadrupole splittings have been investigated for a large number of pcFeL2 and pcFeL1L2 complexes, in which the axial ligands have varying electronic and steric properties. The electron charge densities and electric field gradients at the iron ion were evaluated using a locally dense basis approach with Wachters’ all‐electron basis set for the iron ion, the 6‐311++G(2d) basis set for atoms directly bonded to the iron ion, the 6‐31G(d) basis set for atoms two bonds away from the iron ion, and the 3‐21G* basis set for all other atoms. A good correlation between the theoretical and experimental isomer shifts and quadrupole splittings has been observed for all the complexes tested. It has also been shown that the proposed model for the calculation of Mössbauer spectral parameters is adequate for the evaluation of the axial ligand conformation in cases of conformational flexibility in pcFeL2 complexes.

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Second Generation Nanostructured Metal Oxide Matrices to Increase the Thermal Stability of CO and NO₂ Sensing Layers Based on Iron(II) Phthalocyanine

Fernández-Sánchez

Fernández²,

Steiger³

et al. 2007

Adv Funct Materials

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An iron(II) phthalocyanine (FePc) complex solubilized by decylamine (DA) and benzylamine (BA) is incorporated into a nanoparticulate metal oxide matrix to develop optical sensor films sensitive to NO2 and CO. Eleven amine solvents have been tested as N‐donor ligands that permit ligand exchange with the gas molecules. We have systematically investigated the suitability of different N‐donor ligands, studied the thermal stability of the NO2‐ and CO‐sensing films at 4, 25, 60, and 80 °C by photometry, and corroborated our findings by using NMR experiments. A satisfactory thermal stability of the films has not been obtained for chemically unmodified nanoparticulate metal oxide matrices. We have therefore developed a second generation of nanostructured metal oxide supports that show increased thermal stability and adequate sensitivity to NO2 and CO. These novel nanostructured matrices have been chemically modified using amines, alumina oligomers, and/or anti‐gas‐fading agents. These components have been integrated into the metal oxide matrices to avoid degradation of the optical films and to preserve their sensitivity.

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Mössbauer spectroscopic studies of carbonyl haemochromes; correlations with reactivity

Cited by 20 publications

References 0 publications

Effect of the Sixth Axial Ligand in CS-Ligated Iron(II)octaethylporphyrinates: Structural and Mössbauer Studies

Effect of the Sixth Axial Ligand in CS-Ligated Iron(II)octaethylporphyrinates: Structural and Mössbauer Studies

Mössbauer, Crystallographic, and Density Functional Theoretical Investigation of the Electronic Structure of Bis-Ligated Low-Spin Iron(II) Phthalocyanines

Second Generation Nanostructured Metal Oxide Matrices to Increase the Thermal Stability of CO and NO₂ Sensing Layers Based on Iron(II) Phthalocyanine

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Mössbauer spectroscopic studies of carbonyl haemochromes; correlations with reactivity

Cited by 20 publications

References 0 publications

Effect of the Sixth Axial Ligand in CS-Ligated Iron(II)octaethylporphyrinates: Structural and Mössbauer Studies

Effect of the Sixth Axial Ligand in CS-Ligated Iron(II)octaethylporphyrinates: Structural and Mössbauer Studies

Mössbauer, Crystallographic, and Density Functional Theoretical Investigation of the Electronic Structure of Bis-Ligated Low-Spin Iron(II) Phthalocyanines

Second Generation Nanostructured Metal Oxide Matrices to Increase the Thermal Stability of CO and NO2 Sensing Layers Based on Iron(II) Phthalocyanine

Contact Info

Product

Resources

About

Second Generation Nanostructured Metal Oxide Matrices to Increase the Thermal Stability of CO and NO₂ Sensing Layers Based on Iron(II) Phthalocyanine