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1

Badanie struktury elektronowej i własności magnetycznych monokryształów związków międzymetalicznych R-T (R - pierwiastek ziem rzadkich, T - metal przejściowy 3d, 4d, 5d)

Talik E.

Zeszyty Historyczne Politechniki Warszawskiej

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2014

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z. 16

7--22

2

Determination of total contents of transition metals in selected granular black teas marketed in Poland

Sykuła A., Brodowska K., Więdłocha M.

Biotechnology and Food Science

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2014

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Vol. 78, nr 1

45--52

EN

The total contents of metals in three granulated black tea samples marketed in Poland were determined. Four elements consisting transition metals (Ni, Cu, Zn and Fe) were analyzed using flame atomic absorption spectrophotometry (FAAS). All examined tea brands contain considerable contents of the studied transition metals. Among the tested transition metals Fe (242-589 mg kg-1) was the most abundant one in the granular black tea imported from India. The highest value of Fe was analyzed in the cheapest tea, the smallest in the most expensive. The other metals are less abundant than Fe, their values varied from 8.50-8.90 for Ni, 7.80-10.4 for Cu and 8.13-12.6 for Zn mg kg-1. The accuracy of the proposed method was assessed by determining the recovery of metals from analyzed tea samples using the standard addition method. Recovery assays of nickel, copper, zinc and iron were demonstrated satisfactory, mean recoveries 99.29, 100.31, 99.94 and 99.79 %, respectively.

3

Synthesis and Characterization of a New Unsymmetrical Porphyrin Liquid Crystal and Its Metal Complexes

Zhuang C. -F., Tang X. -X., Wang D., Lian W. -H., Xia A. -Q., Shi Y. -H., Shi T. -S.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 12

2205-2213

EN

Meso-substituted unsymmetrical porphyrin liquid crystal, 5-(p-palmitoyloxy phenyl)phenyl-10,15,20-triphenyl porphyrin (PPTPPH2) and relative transition metal complexes (PPTPPM, M = Zn, Co, Mn, Cu, FeCl) were synthesized and characterized by means of elemental analysis, UV-Vis, IR, MS and 1H NMR spectroscopies. Further more, the thermal stabilities and fluorescence spectroscopy of these complexes were investigated. The liquid crystal properties were investigated by differential scanning calorimetry (DSC) and polarized optical microscopy (POM). The results reveal that the PPTPPH2 shows liquid crystalline behavior with more than one mesophase and it has a low-lying phase transition temperature, which changes from 3.9 to 73.5°C.

4

Hydrothermal Synthesis, Structure Characterization of a New Mixed Mo/V Metal-Oxygen Cluster Compound: [Co(phen)3]2[HPMoV4 MoVI4V IV6 M2O44]×4H2O, (M = 0.78MoV + 0.22V IV)

Sun Y. H., Li X. P., Sun D. H., Niu L., Xu J. Q.

Polish Journal of Chemistry

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2007

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Vol. 81, nr 9

1567-1575

EN

A new polyoxometalat[Co(phen)3]2[HPMoV4 MoVI4V IV6 M2O44]×4H2O, (M = 0.78MoV + 0.22V IV)e 1 was hy dro ther mally syn the sized and char ac ter ized by IR, el e men tal anal y ses, X-ray pho to elec tron spec trum, ESR and sin gle crys tal X-ray dif frac tion. The ti tle com - pound is in the triclinic space group P1 with a = 12.0953(7) A, b = 14.0182(6) A, c = 14.6468(7) A, V = 2402.55(18) A3, a = 105.134(2), b = 91.841(3), g = 91.401(2), Z = 1, and R1 (wR2) = 0.0617 (0.1701). The compound was prepared from tetra-capped pseudo-Keggin with phosphorus-centered polyoxoanions [PMo8V6M2O44]5-, [Co(phen)3]2+ cations and linked through hydrogen bonds and p-p stacking inte action into three-dimensional supramolecular framework. A study of the magnetic properties of 1 demonstrates that it exhib its antiferromagnetic coupling interactions.

5

Catalytic degradation of polystyrene - Rapid Communication

Kijeński J., Kaczorek T.

Polimery

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2005

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T. 50, nr 1

60-63

EN

Syndiotactic polystyrene was degraded in an atmosphere of N2 or H2 at 375 or 400 degrees C in the presence of transition metal catalysts (Cr, Ni, Mo, Co or Fe) on the support (Al2O3, SiO2). Styrene, ethyl benzene, a-methylstyrene, cumene, toluene, benzene as well as bi- and tricyclic hydrocarbons were found in the reaction products. Effects of degradation conditions on the products compositions were discussed. The highest yield of styrene monomer (>80 %) was reached when iron-based catalysts were used.

PL

Syndiotaktyczny polistyren degradowano w atmosferze N2 lub H2 w temp. 375 stopni C i 400 stopni C w obecności metali przejściowych (Cr, Ni, Mo, Co, Fe) na nośniku (Al2O3, SiO2) jako katalizatorów. W produktach reakcji stwierdzono obecność styrenu, etylobenzenu, a-metylostyrenu, kumenu, toluenu, benzenu oraz węglowodorów dwu- i trójpodstawionych (tabele 1 i 2). Omówiono wpływ warunków degradacji na skład jej produktów. Największą wydajność monomerycznego styrenu (>80 %) uzyskano z zastosowaniem katalizatorów żelazowych.

6

Hydrogen Atom and Hydrogen Ion Interactions with the [100] Surface of Transition Metals (Pd, Ni, Ag, Cu)

Bartczak W., Romanowski S., Stawowska J.

Polish Journal of Chemistry

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2004

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Vol. 78 / nr 9

1103-1119

EN

Quantum calculations of interaction of the atomic hydrogen with metal (Pd, Ni, Ag, Cu) clusters with the structure of the fcc [100] surface have been performed. The calculations have been based on the gradient-corrected methods of the Density Functional Theory. For a given position (X,Y) of the hydrogen atom over the metal plane the distance Z from the plane was optimized in order to obtain the highest binding energy which was defined as the difference between the total energy of the H-Me cluster and the energy of the separate H atom and metal cluster. The results of the calculations allowed us to construct the Potential Energy Surfaces for a series of systems. It appears that the H atom binding energy along the valley perpendicular to the metal-metal bond varies only slightly. This suggests easy diffusion of hydrogen along this path. The potential barrier for the hydrogen diffusion over palladium surface is of the order of 0.17 eV. In the case of Ni, Ag and Cu we observe potential barriers with a maximum above the metal-metal bond, with the barrier height 0.68 eV, 0.62 eV and 0.79 eV, respectively. Separate calculations have been performed for the positively charged clusters. For the case of the charged clusters the potential barriers are lower than the value for the neutral clusters. The barriers are 0.27 eV for Ni, 0.35 eV for Ag and 0.58 eV for Cu. For Pd the barrier for the positively charged cluster is 0.5 eV, higher than the value for the neutral case, but for the negatively charged cluster the barrier is practically 0.The results of calculations for all the cases considered suggest the possibility of easy, sometimes activationless, diffusion of hydrogen atoms over the metal surface.

7

Redukcja tlenków azotu wobec podpieranych montmorylonitów modyfikowanych jonami metali przejściowych

Chmielarz L., Kustrowski P., Zbroja M., Dziembaj R.

Przemysł Chemiczny

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2003

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T. 82, nr 8-9

678-681

8

Katalityczne zastosowania azotków i węglików metali przejściowych

Szymańska A., Lewandowski M.

Przemysł Chemiczny

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2003

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T. 82, nr 5

335-341

9

Crystal structure and magnetic properties of RTSi2 compounds (R - rare earth, T - transition metal)

Gil A.

Prace Naukowe. Chemia / Wyższa Szkoła Pedagogiczna w Częstochowie

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2003

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Vol. 8

165--175

EN

The ternary intermetallics containing rare earth have particularly intriguing magnetic properties. In this work properties of RTSi2 compounds are discussed (R - rare earth, T - transition metal). Most of the RTSi2 compounds crystallize in the orthorhombic CeNiSi2 - type structure (space group Cmcm). Some of them crystallize in orthorhombic TbFeSi2 and YlrGe2 or monoclinic NdRuSi2 - type structure, which are closely related to CeNiSi2 structure. They were found to display various types of magnetic ordering: ferromagnetic, collinear antiferromagnetic, sine wave modulated or helicoidal. The magnetic properties of the RTSi2 compounds are analyzed in terms of the RKKY theory and crystal electric field effect.

10

Synthesis, Spectral Properties and Antitumor Activity of Some Transition Metal Complexes with a Schiff Base Ligand

Tai X., Yin X., Tan M.

Polish Journal of Chemistry

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2003

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Vol. 77 / nr 4

411-414

EN

Four complexes of transition metals, namely: [Mn(L)2] (complex 1), [Ni(L)2ź0.5H2O] (complex 2), [Cu(L)2ź4H2O] (complex 3) and [Zn(L)2ź0.5H2O] (complex 4), (L = Schiff base derived from trimethylol amino methane and salicylic aldehyde), have been synthesized. The complexes were characterized by elemental analysis, IR, 1H NMR, UV and TG-DTA spectra. Tentative structures for the complexes have been proposed. The antitumor activity against HL-60 human leukemia cells of free ligand and its Mn, Ni, Cu complexes were studied by MTT method.

11

Transition metal chlorides complexes with tetrahydrofuran [MtCl(4)(THF)(2)] used as precursors of ethylene polymerization catalysts

Szczegot K., Flisak Z., Sibelska I., Dawidowska-Marynowicz B.

Polimery

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2002

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T. 47, nr 2

85-89

EN

Three complexes of transition metal chlorides with tetrahydrofuran (THF), viz., [TiCl4(THF)(2)] (I), [ZrCl4(THF)(2)] (II), and [HfCl4(THF)(2)] (III), were prepared and studied as the precursors of titanium-magnesium catalysts to be used in low-pressure polymerization (0.5 MPa, 323 K) of ethylene using AlEt3 (most favorable), AlEt2Cl, or Al(i-Bu)(3) as cocatalysts. The activity of catalysts increases in the order [HfCl4(THF)(2)] < [ZrCl4(THF)(2)] < [TiCl4(THF)(2)]. Degree of crystallinity (C), density, bulk density, M, MWD, and m.p. were determined for the resulting HDPE. Catalyst activity, found to obey the following ascending type (III) < (II) < (I), increased as the element electronegativity was raised and the partial charge on the transition metal atom in the precursor was diminished. The catalyst surface patterns visualized by a computer supported the experimental data. The uncomplexed, [MgCl2(THF)(2)]-supported tetrachlorides yielded catalysts less active than (I)-(III), but following the same general activity correlations.

PL

Otrzymano trzy kompleksy chlorków metali przejściowych z THF - [TiCl4(THF)2] (I), [ZrCl4(THF)2] (II), oraz [HfCWTHF),] (III) i zastosowano je jako prekursory katalizatorów tytanowo-magnezowych w niskociśnieniowej polimeryzacji (0,5 MPa, 323 K) etylenu przy użyciu AlEt3 (najkorzystniej), AlEt2Cl lub Al(z'-Bu)3 jako kokatalizatora (rys. 1, tabela 1). Zmierzono gęstość, gęstość nasypową, stopień krystaliczno-ści, ciężary cząsteczkowe i ich rozkład oraz temperaturę topnienia uzyskanego PE-HD (tabela 1). Aktywność katalizatorów wzrastała w szeregu (III) < (II) < (I), tzn. ze wzrostem elektroujemności pierwiastka metalu i ze spadkiem wartości ładunku cząstkowego na atomie metalu grupy przejściowej w cząsteczce prekursora (tabela 3). Uzyskane dane doświadczalne zostały potwierdzone przez komputerowe wykresy powierzchni katalizatora (rys. 2-6). Katalizatory zawierające nieskompleksowane z THF czterochlorki osadzone na [MgCl2(THF)2] były mniej aktywne od katalizatorów (I)-(III), ale także spełniały zależności ogólne (rys. 1).

12

Thermochemical and Spectral properties of Hydrates of Co(II), Ni(II) and Cu(II) Maleate. Crystal Structure of Co(II) Maleate Trihydrate

Pajtasova M.

Polish Journal of Chemistry

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2001

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Vol. 75, nr 9

1209-1217

EN

The crystal and molecular structure of Co(II) maleate trihydrate, Co(C4H2O4)_3H2O, was determined by direct method and Fourier techniques. The structure was refined by full-matrix least-squares methods to a weighted R factor of 0.0263, based on independent reflections. The compound is a three-dimensional coordination polymer with distorted octahedron geometry at each cobalt(II) centre. Each cobalt atom is six-coordinated through two oxygen atoms from water molecules and four oxygen atoms from four different maleate groups. The thermal decompositions of Co(mal)_3H2O, Ni(mal)_3H2O and Cu(mal)_H2O(mal = maleate) have been investigated by means of TG, DTG, DSC and IR spectra. The release of volatile molecules after heating is either a three-step process for Co(mal)_3H2O and Ni(mal)_3H2O or a two-step process for Cu(mal)_H2O.