Wszystkie pola: Kaczmarzyk, T.

Skocz do pozycji: 1.

Tytuł:: Spectroscopic characteristics of FeI-phthalocyanine
Autorzy:: Kaczmarzyk, T.
Jackowski, T.
Dziliński, K.
Tematy:: iron phthalocyanine
reduction process
Mössbauer spectroscopy
EPR
DTF; Pokaż więcej
Wydawca:: Instytut Chemii i Techniki Jądrowej
Powiązania:: https://bibliotekanauki.pl/articles/148333.pdf Link otwiera się w nowym oknie
Opis:: Results of Mössbauer and EPR study of a univalent-iron phthalocyanine complex (FeIPc) are presented in this paper. FeIPc has been obtained from FeIIPc by the chemical reduction method in tetrahydrofuran (THF) and dimethoxyethan (DME) solutions. Like in the case of FeI-porphyrin complexes, Mössbauer and EPR data as well as quantum calculations of electronic absorption spectra confirm in this case a low-spin configuration of FeI ions with an unpaired electron located at dz2 orbital. Interaction between FeIPc and THF molecules does not change significantly the electron configuration of FeI ions coordinated to phthalocyanine ligand.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 2.

Tytuł:: Mössbauer spectroscopy of reduced forms of a Fe-tetraphenylporphyrine complex
Autorzy:: Kaczmarzyk, T.
Rutkowska, I.
Dziliński, K.
Tematy:: DFT calculations
electronic structure
iron-(tetraphenyl)porphyrin
Mössbauer spectroscopy
reduction process; Pokaż więcej
Wydawca:: Instytut Chemii i Techniki Jądrowej
Powiązania:: https://bibliotekanauki.pl/articles/148211.pdf Link otwiera się w nowym oknie
Opis:: Molecular and electronic structure changes during successive reduction of a Fe-tetraphenylporphyrin chloride [Fe(III)(TPP):Cl] complex are reported on the basis of Mössbauer spectroscopy and DFT calculations. It is established that the attachment of additional electrons to a neutral Fe(III)(TPP):Cl molecule leads to signifi cant shortening of Fe-N distances at the fi rst stage of the reduction Fe(III)(TPP):Cl →Fe(II)(TPP) and lengthening of these bonds at the second stage Fe(II)(TPP)→Fe(I)(TPP). Changes of other bond lengths of the porphyrin ring also appear but in less degree. Interaction of Fe(II) and Fe(I)(TPP) with tetrahydrofuran (THF) solvent is considered. Electron configuration of Fe(II)(TPP) corresponds to intermediate-spin (S = 1) state and in the case of Fe(I)(TPP) low-spin state (S = ½) is observed. Electron density distribution in Fe(II)- and Fe(I)(TPP) complexes, in association with Mössbauer data, is analyzed. Good correlation between experimental and theoretical results was obtained.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 3.

Tytuł:: Mössbauer Study of a Reduction Process in Iron Azaporphyrins
Autorzy:: Kaczmarzyk, T.
Jackowski, T.
Dziliński, K.
Kania, L.
Tematy:: 33.15.-e; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Powiązania:: https://bibliotekanauki.pl/articles/1808101.pdf Link otwiera się w nowym oknie
Opis:: Electronic structure of the Fe(II)- and Fe(I)-complexes of mono- and diazaporphyrins studied by the Mössbauer spectroscopy is considered in this paper. It was found that in the presence of tetrahydrofuran molecules, the electron configuration of Fe(II) ions in the studied complexes corresponds to the intermediate spin state (S = 1) and the complexation of tetrahydrofuran solvent does not change this state. Interaction of tetrahydrofuran solvent with Fe(I)-azaporphyrins does not influence the electronic structure of Fe(I) ions coordinated to the porphyrin ligand, either. Electron configuration of Fe(I) ions in Fe(I)-octaethylporphyrins and Fe(I)-azaporphyrins is the same: ($d_{xy})^{2}(d_{xz},d_{yz})^{4}(d_{z}^2)^{1}$. The aza substitution is reflected in the values of the Mössbauer parameters. Increasing number of nitrogen atoms at meso positions causes the increase in the quadrupole splittings within the range 1.49-2.24 mm/s for the Fe(II) complexes and within the range 1.35-1.85 mm/s for the Fe(I)-porphyrins. Values of the isomer shifts are decreased from 0.51 to 41 mm/s for the same sequence of the Fe(II) complexes. For the Fe(I) reduced forms the isomer shifts are nearly constant and equal to about 0.37 mm/s. The Mössbauer results are discussed in association with EPR data for Fe(I)-porphyrins.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 4.

Tytuł:: Univalent iron monoazaetioporphyrin complexes studied by Mössbauer spectroscopy
Autorzy:: Kaczmarzyk, T.
Dziliński, K.
Sinyakov, G.
Egorova, G.
Tematy:: EPR
iron porphyrins
Mössbauer spectroscopy
reduction reactions; Pokaż więcej
Wydawca:: Instytut Chemii i Techniki Jądrowej
Powiązania:: https://bibliotekanauki.pl/articles/148854.pdf Link otwiera się w nowym oknie
Opis:: Results of Mössbauer and EPR studies of univalent-iron monoazaetioporphyrin complexes [Fe(I)(MAEP)] are presented in this paper. Fe(I)(MAEP) were generated using the chemical reduction method. Three forms of the univalent-iron monoazaetioporphyrin complexes were observed: (I) typical Fe(I)(MAEP), (II) with an additional electron on the porphyrin ligand [Fe(I)(MAEP•)]- and (III) the Fe(I)(MAEPh) phlorin structure. Electron configuration of Fe(I) ions in these complexes is (dxy)2(dxz ,dyz)4(dz 2)1. The [Fe(I)(MAEP•)]- structure is stable only in solution and it is transferred into Fe(I)(MAEP) in the solid state. Mössbauer parameters for all products of the reduction reaction are given.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 5.

Tytuł:: Effect of nitrogen substitution in porphyrin ring on Mössbauer parameters of iron ions
Autorzy:: Kaczmarzyk, T.
Jackowski, T.
Dziliński, K.
Sinyakov, G.
Tematy:: Mössbauer spectroscopy
iron porphyrins
azaporphyrins
trivalent-iron spin states; Pokaż więcej
Wydawca:: Instytut Chemii i Techniki Jądrowej
Powiązania:: https://bibliotekanauki.pl/articles/147210.pdf Link otwiera się w nowym oknie
Opis:: Electron configuration changes of Fe(III) ions in porphyrin complexes with chloride axial ligands caused by the successive nitrogen substitution of CH methine bridges at meso positions of the porphyrin ring is discussed on the basis of Mössbauer spectroscopy results. It was shown that increase of a number of nitrogen atoms at the meso positions changes the character of quantum-mechanically mixed spin state of Fe(III) ions (S = 5/2 + 3/2) by the increase of the intermediate-spin (S = 3/2) contribution. This feature is reflected in Mössbauer spectra by an increase of quadrupole splitting values and the decrease of the asymmetry of quadrupole doublets, when the number of nitrogen atoms at the meso positions increases. Isomer shifts remain practically unchanged. These peculiarities are discussed in the light of spin relaxation mechanisms and the occupancy of d orbitals in Fe(III) ions coordinated to the porphyrin ring and chloride ligand. It has been noticed that Mössbauer parameters correlate qualitatively with EPR data.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 6.

Tytuł:: Asymmetry in Mössbauer spectra of FeIII-azaporphyrin complexes
Autorzy:: Kaczmarzyk, T.
Jackowski, T.
Dziliński, K.
Sinyakov, G.
Tematy:: Mössbauer spectroscopy
iron porphyrins
azaporphyrins
asymmetry in Mössbauer spectra
spin-spin and spin-lattice relaxation; Pokaż więcej
Wydawca:: Instytut Chemii i Techniki Jądrowej
Powiązania:: https://bibliotekanauki.pl/articles/148331.pdf Link otwiera się w nowym oknie
Opis:: Temperature dependence of asymmetry as well as isomer shift and quadrupole splitting values of Mössbauer spectra of trivalent iron complexes coordinated to porphyrin ligands such as octaethylporphyrin, monoazaethioporphyrin, diazaoctaethylporphyrin and phthalacyanine is discussed in this paper. All the above mentioned complexes have the chloride axial ligand at the fifth coordination site. Different temperature changes of asymmetry and other parameters of Mössbauer spectra of these complexes can be correlated with a number of methine bridges CH substituted by nitrogen atoms in the porphyrin macrocycle. The form of this asymmetry is such that the higher-energy component of the doublet is more broadened than the lower-energy one, while the areas (intensities) under each of two components are the same. The most distinct asymmetry is observed at room temperature. When temperature is decreasing, the spectrum becomes successively more symmetrical and at liquid helium temperature linewidths of both components of the quadrupole splitting are very close one another. The Mössbauer spectrum of the FeCl-monoazaethioporphyrin complex exhibits reversed asymmetry at liquid helium temperature in comparison with the spectra of the remaining complexes i.e. the lower-energy component of the doublet is slightly more broadened than the higher-energy one. The spin-spin and spinlattice relaxation mechanisms in the context of quantum mechanically mixed spin states S = 5/2 + 3/2 of FeIII ions are considered as a source of the observed asymmetry.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 7.

Tytuł:: Spectroscopic study of a bis(imidazole) (octaethylporphyrinato)iron(III) complex
Autorzy:: Rutkowska, I.
Dziliński, K.
Kaczmarzyk, T.
Stanek, J.
Tematy:: electron paramagnetic resonance (EPR) spectroscopy
Mössbauer spectroscopy
low-spin iron porphyrin
imidazole axial ligands; Pokaż więcej
Wydawca:: Instytut Chemii i Techniki Jądrowej
Powiązania:: https://bibliotekanauki.pl/articles/146898.pdf Link otwiera się w nowym oknie
Opis:: Low-spin ferric octaethylporphyrinatoiron complex with two imidazole axial ligands [Fe(III)(OEP)(Im)2]+ has been investigated by electron paramagnetic resonance (EPR) and Mössbauer spectroscopies. It was found that the ground spin state corresponds to the electron configuration (dxy)2 (dxz, dyz)3 and planes of the imidazole axial ligands have a parallel mutual orientation. Ethyl groups bonded to pyrrole rings, as peripheral substituents, effect on the ground electron spin state of the complex studied and the relative orientation of the the imidazole axial ligands in a similar way like the phenyl substituents bonded to meso-carbon atoms of the porphyrin macrocycle. The temperature dependence of the Mössbauer spectra is discussed in terms of magnetic relaxation processes.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 8.

Tytuł:: Własności optyczne oraz struktura molekularna silikonów na bazie para-(thio)phenoxyphenylu oraz para-(thio)phensulfaphenylu
The optical properties and molecular structure of silicone-based para-(thio)phenoxyphenyle and para-(thio)phensulfaphenyle
Autorzy:: Dośpiał, M.
Kaczmarzyk, T.
Matusiak, R.
Gacek, M.
Tematy:: polimer
silikon
struktura molekularna
struktura geometryczna
widmo absorpcyjne
właściwości optyczne
implant
soczewka wewnątrzgałkowa
polymer
silicon
molecular structure
geometrical structure
absorption spectrum
optical properties
intraocular lens; Pokaż więcej
Wydawca:: Sieć Badawcza Łukasiewicz - Instytut Inżynierii Materiałów Polimerowych i Barwników
Powiązania:: https://bibliotekanauki.pl/articles/278062.pdf Link otwiera się w nowym oknie
Opis:: W pracy dokonano teoretycznej analizy własności optycznych oraz struktury molekularnej materiałów opartych na silikonach stosowanych do produkcji implantów w postaci soczewek wewnątrzgałkowych. Badania teoretyczne struktury i właściwości optycznych wykonane zostały w pakiecie ADF w oparciu o półempiryczną metodę DFT bazującą na podejściu Kohn-Shama. Na podstawie przeprowadzonych badań teoretycznych określono parametry struktury badanych polimerów, takie jak: kąty dihedralne oraz odległości miedzyatomowe. Wyznaczone widma absorpcyjne zostały zestawione z rozkładami wrażliwości fotoreceptorów. Na podstawie uzyskanych wyników stwierdzono obecność maksimum absorpcyjnego w zakresie promowania widzialnego dla związku para-(thio)phensulfaphenylu. Obecność takiego maksimum w zakresie światła widzialnego jest niepożądana i może prowadzić do zaburzeń w postrzeganiu barw.
The paper presents a theoretical analysis of the optical properties and molecular structure of the silicone-based materials used for the manufacture of implants in the form of intraocular lenses. Theoretical studies of the structure and optical properties has been made in the ADF package based on semi-empirical method based on DFT Kohn-Sham approach. On the basis of theoretical studies the structure parameters of investigated polymers has been determined, such as: dihedral angles and interatomic distances. Designated absorption spectra were exhibited together with the photoreceptor sensitivity distributions. Obtained results revealed the presence of absorption maximum in the visible wave range for the para-(thio)phensulfaphenyle. The presence of such a maximum is undesirable and may lead to disturbances in the color perception.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 9.

Tytuł:: Mössbauer study of a tetrakis (pentafl uorophenyl) porphyrin iron (III) chloride in comparison with the fluorine unsubstituted analogue
Autorzy:: Kaczmarzyk, T.
Dziedzic-Kocurek, K.
Rutkowska, I.
Dziliński, K.
Tematy:: catalytic activity
DFT calculations
electronic structure
iron(III)-[tetrakis (pentafl uorophenyl)]
Mössbauer spectroscopy
porphyrin chloride; Pokaż więcej
Wydawca:: Instytut Chemii i Techniki Jądrowej
Powiązania:: https://bibliotekanauki.pl/articles/146091.pdf Link otwiera się w nowym oknie
Opis:: Mössbauer investigations, in association with density functional theory (DFT) calculations, have been conducted for the molecular and electronic structures of iron (III) [tetrakis (pentafl uorophenyl)] porphyrin chloride [(F20TPP)Fe:Cl], as a Fe(III)-tetraphenylporphyrin complex containing chloride axial ligand and substituted hydrogen atoms by fl uorine ones in the four phenyl rings, in comparison with its fl uorine unsubstituted analogue [(TPP)Fe:Cl]. It was found that the parameters of Mössbauer spectra of both complexes are close to one another, and correspond to the high-spin state of Fe(III) ions, but they show the different temperature dependence and the quadrupole doublets in Mössbauer spectra show different asymmetry at low temperatures. Results of DFT calculations are analyzed in the light of catalytic activity of the halogenated complex.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Skocz do pozycji: 10.

Tytuł:: The microstructure and magnetic properties of Nd8.5Tb1.5Fe83Zr1B6 ribbons obtained at various cooling rates
Autorzy:: Dośpiał, M.
Olszewski, J.
Nabiałek, M.
Pietrusiewicz, P.
Kaczmarzyk, T.
Tematy:: microstructure analysis
Mössbauer spectroscopy
permanent magnets
reversal magnetization; Pokaż więcej
Wydawca:: Instytut Chemii i Techniki Jądrowej
Powiązania:: https://bibliotekanauki.pl/articles/147459.pdf Link otwiera się w nowym oknie
Opis:: The paper presents results of microstructure and magnetic properties studies of Nd8.5Tb1.5Fe83Zr1B6 ribbons obtained by melt-spinning technique. The samples were produced using the rapid cooling of liquid alloy on the copper wheel, by applying three different linear velocities 20, 30, and 35 m/s. The microstructure of obtained ribbons was examined using X-ray diffractometry and Mössbauer spectroscopy. Magnetic measurements were performed using LakeShore vibrating sample magnetometer. The microstructure measurements were used for quantitative and qualitative analysis of phase composition. Basing on results of structure studies combined with magnetic measurements, the infl uence of phase composition on hysteresis loop behavior was described.
Dostawca treści:: Biblioteka Nauki

Artykuł

na półce

Informacja

Wyszukujesz frazę "Kaczmarzyk, T." wg kryterium: Wszystkie pola