Wyniki wyszukiwania - BazTech

1

Reduction of NO with methane over metal ion-exchanged mordenite

Ćwikła-Bundyra W.

Ars Separatoria Acta

|

2011

|

No. 8

109-119

EN

This article presents the results of research studies on the possibilities of application of natural zeolite-mordenite for the reduction of nitrogen oxide. Various kinds of metal ions were added to the zeolite samples using the ion-exchange method. The effect of metal contents was shown for the mordenite and related to their catalytic properties. The catalytic properties of Cu-, Co-, Ni- were compared for NO reduction with methane. High nitric oxide conversions were observed for copper and cobalt-mordenite, especially in the temperature range between 400 and 500 C degree. Copper- and cobaltmordenite catalysts showed higher activities and selectivities than catalysts composed of nickel-exchanged mordenite.

2

Adsorption of heavy metal ions at the Al2O3-SiO2/NaClO4 electrolyte interface

Skwarek E., Matysek-Nawrocka M., Janusz W., Zarko V. I., Gun'ko V. M.

Physicochemical Problems of Mineral Processing

|

2008

|

Vol. 42

153-164

EN

The study on adsorption of heavy metals (Cd(II), Ni(II) and Pb(II)) at the Al2O3-SiO2/electrolyte solution interface is presented in this paper. The influence of ionic strength, pH, background electrolyte (NaClO4) concentration and composition of metal oxide on adsorption of Cd(II), Ni(II) and Pb(II) from solution of initial concentration ranged from 1×10-6 to 1×10-3 mol/dm3 in the mentioned system was investigated. The adsorptions edge parameters (pH50% and pH10-90%) for different concentrations of electrolyte were presented. The adsorption measurements were complemented by the potentiometric titration of Al2O3-SiO2 suspensions and electrophoretic measurements. Charge reversal point (CR2) can be observed for solution concentration of 10-3 mol/dm3 as a result of Cd(II), Ni(II) and Pb(II) ions adsorption.

PL

Kadm, ołów i nikiel są toksycznymi metalami ciężkim, który stanowią wciąż poważne zagrożenie dla organizmów żywych. W środowisku naturalnym oraz w wielu procesach technologicznych mamy do czynienia ze skomplikowanymi układami gdzie występują obok siebie tlenki typu Al2O3-SiO2 oraz jony metali ciężkich. Przeprowadzono badania adsorpcji jonów niklu, kadmu i ołowiu dla różnych stężeń początkowych, w funkcji pH dla układów AS1, AS3, AS8/roztwór NaCl. Kształt krzywych adsorpcji w funkcji pH ma postać krawędzi adsorpcji. Wzrost stężenia początkowego jonów metali ciężkich, powoduje przesunięcie krawędzi w kierunku zasadowym skali pH. Wyznaczono charakterystyczne parametry krawędzi adsorpcji tj. pH50% i apH10-90%, w oparciu o zależność adsorpcji od pH stosując model TLM, obliczono równieS stałe reakcji adsorpcji jonów Ni(II), Cd(II), Pb(II) metodą optymalizacji numerycznej. Zależność gęstości ładunku powierzchniowego od pH w obecności jonów metali ciężkich, jest w dobrej korelacji z zależnością adsorpcji jonów Ni(II), Cd(II), Pb(II) od pH. Adsorpcja badanych jonów na powierzchni AS1, AS3, AS8 prowadzi do wzrostu stężenia grup ujemnie naładowanych.

3

Reactions of Complexation of Co(II), Ni(II), Cu(II), Cd(II) and Hg(II) Ions with Adenosine 5'-Diphosphate

Łomozik L., Gąsowska A., Bregier-Jarzębowska R.

Polish Journal of Chemistry

|

2004

|

Vol.78 /nr 11-12

2023-2035

EN

The reaction of complexation has been studied in the systems of the ions: Co(II), Ni(II), Cu(II), Cd(II) and Hg(II) with adenosine 5_-diphosphate. The composition and stability constants of the complexes formed have been determined by the potentiometric method. The presence of the species type: MHL, MLx, and MLOH has been confirmed and their mode of coordination has been identified on the basis of the spectral data. In the acidic solution, the coordination dichotomy N(1)/N(7) has been found in all systems studied. At pH above 7, the dichotomy does not occur in the systems with Cu(II), while in the systems with Hg(II) only phosphate groups are involved in metallation. In the synthesized solid complexes of Cd(II) with AMPor ADP, the metal ion is bound by the donor nitrogen atom N(1), and in the complexes with ATP by the nitrogen atom N(7) of the nucleotide. Moreover, in the species with adenosine di- and triphosphate, the oxygen atoms of the phosphate groups are engaged in the complexation, while in the species Cd(AMP), similarly as in the liquid phase, the phosphate group is not involved in metallation.

4

The Synthesis and Characterization of 1,2-dihydroxyimino-3,6-di-aza-8,9-O-iso-butylidene Nonane and Its Complexes with Ni(II), Cu(II), Zn(II) and Cd(II)

Canpolat E., Kaya M., Görgülü A. O.

Polish Journal of Chemistry

|

2002

|

Vol. 76 / nr 5

687-694

EN

1,2-Dihydroxyimino-3,6-di-aza-8,9-O-iso-butylidene nonane (H2L) was synthesized starting from 1,2-O-iso-butylidene-4-aza-6-amino hexane (RNH2) and antichloroglyoxime. Ni(II) and Cu(II) complexes ofH2L have a metal:ligand ratio of 1:2 and the ligand coordinates through two N atoms, as do most of the vic-dioximes. However, Zn(II) and Cd(II) complexes of H2L have a metal:ligand ratio of 1:1 and one chloride ion and one water molecule are also coordinated to the metal ion. Structures of the ligand and its transition- metal complexes are proposed, according to elemental analyses, IR, 13C and 1H NMR spectra, magnetic susceptibility measurements and thermogravimetric analyses (TGA).

5

Interaction Centers of Purine and Pyrimidine Nucleotides in Their Reactions with Cu(II), Ni(II), Co(II), Cd(II) and Hg(II) Ions

Gąsowska A., Bregier-Jarzębowska R., Łomozik L.

Polish Journal of Chemistry

|

2002

|

Vol. 76 / nr 6

773-783

EN

It has been established that in ATP complexes with Cu(II), Co(II) and Cd(II) ions, the metallation centres are the oxygen atoms of the phosphate group and the nitrogen atom N(7) from the purine ring. The spectral data suggest some involvement of N(1) atom in these interactions. In the ATP complexes with Ni(II) the main centres of coordination were found to be N(7) and N(1), while the contribution of the oxygen atoms from the phosphate group is of secondary importance. In the ATP complexes with Hg(II) ions, above pH 7, the metallation involves only the oxygen atoms from the phosphate group, while the N(1) and N(7) atoms are outside the inner sphere of coordination. In the complexes of CTP with the metal ions studied the interaction centres are the oxygen atoms from the phosphate group and N(3) from the pyrimidine ring. However, in the case of complexes with Ni(II), the main centre of interaction is N(3), while the involvement of the oxygen atoms from the phosphate group is of minor importance.

6

Removal of Ni(II) from aqueous solutions using fly ash and montmorillonite

Banerjee S., Jayaram R.V.

Polish Journal of Chemical Technology

|

2002

|

Vol. 4, nr 4

6-10

EN

Adsorption of toxic metal ions like Ni(II) on heat treated montmorillonite, fly ash and impregnated fly ash was studied in terms of different parameters like initial metal ion concentrations, pH and temperature. Impregnated fly ash (IFAA1) showed much higher levels of adsorption capacity as compared to fly ash and heat-treated montmorillonite. The various rate parameters of the adsorption process have also been determined. Equilibrium adsorption model was arrived, based on Langmuir isotherm and the corresponding constants have been evaluated. Thermodynamic studies have also been carried out and values of standard free energy (AG°), enthalpy (AH°) and entropy (AS°) were calculated. The adsorption was found to be exothermic by these studies.

7

Synthesis and Characterization of a New Thiazole Schiff Base 5-Bromo-2-hydroxybenzylidene-2-aminobenzothiazole and Its Complexes with Co(II), Cu(II) and NiSaII)

Saydam S., Alkan C.

Polish Journal of Chemistry

|

2001

|

Vol. 75, nr 1

29-33

EN

A new ligand 5-bromo-2-hydroxybenzylidene-2-aminobenzothiazole has been synthesized from 2-aminobenzothiazole and 5-bromosalicylaldehyde by condensation in ethanol. Metal complexes of the ligand were prepared from chloride salts of Co(II), Cu(II), and Ni(II) in ethanol. Characterization of the ligand and its complexes were carried out by microanalyses, magnetic susceptibility measurements, FT-IR, 13C, 1H NMR, and UV-Visible spectroscopy. It was suggested that two ligands with two water molecules coordinate to each metal atom by hydroxy oxygen and imino nitrogen to form high spin distorted octahedral complexes with Co(II), Ni(II) and Cu(II).

8

Synthesis, Properties and Thermal Decomposition of Bipyridine-Oxalato Complexes with Mn(II), Co(II), Ni(II) and Cu(II)

Czakis-Sulikowska D., Malinowska A., Radwańska-Doczekalska J.

Polish Journal of Chemistry

|

2000

|

Vol. 74, nr 5

607-614

EN

New mixed-ligand complexes of the following stoichiometric formulae. They have been characterized by IR and VIS spectra and thermoanalysis in air. The central atoms M(II) form coordinate bonds with title ligands.

9

Nucleophilic additions in Cu(II), Ni(II), Co(II) pseudohalide-4-halogenopyrazole systems

Hvastijova M., Kohout J., Mroziński J., Jager L.

Polish Journal of Chemistry

|

1999

|

vol. 73 nr 2

271-278

EN

From M(II)-Y--4-X-pz systems, where M=Cu, Ni, Co; Y=NCO, C(CN)3, N(CN)2; X=Cl, Br, I (pz = pyrazole), new compounds of the type [MY2(4-X-pz)2] and [M(4-X-pz×Y)2] have been prepared. Compounds [M(4-X-pz×Y)2] arise by nucleophylic addition of imine nitrogen from 4-X-pz to cyano carbon of the pseudohalide under formation of five-membered metallocycle. The influence of X substituent on the course of this reaction with various M(II) and Y was investigated. An uncomplete course of nucleophilic addition is revealed by formation of mixed products, consisting of [MY2(4-X-pz)2] and [M(4-X-pz×Y)2]. All compounds were studied by infrared and electronic spectroscopy and probable structures were assigned to the relevant species.

10

Cobalt(II), nickel(II) and copper(II) complexes with adenosine 5'-monophosphate and cytidine 5'-monophosphate in aqueous solutions and in solids

Gąsowska A., Łomozik L.

Polish Journal of Chemistry

|

1999

|

vol. 73 nr 3

465-474

EN

Determination of stability constants and calculation of distribution of complexes formed by Co(II), Ni(II) and Cu(II) with adenosine monophosphate (AMP) and cytidine monophosphate (CMP) were performed by using computer -aided analysis of potentiometric titration data. On the basis of the comparison of the protonation constants of free ligands and MHL-type complexes the proton localization in the coordination compounds was established. The coordination mode in complexes in solution as well as in solids was determined from the results of spectral as well as equilibrium studies. Formation of macrochelate complexes and the occurrence of coordination dichotomy of the N(1)N(7) type as well as N(1)N(7)/O (phosphate group) was evidenced. Contrary to the similar complexes with Cu(II) and Co(II), the phosphate group of the nucleotide becomes essentially involved in the interactions with Ni(II) ions only at high pH values. The modes of coordination in aqueous solution and solid complexes are compared.