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Synthesis, Spectral, Redox and Biological Screening Studies of Schiff Base Copper(II), Nickel(II), Cobalt(II), Oxovanadium(II) and Zinc(II) Complexes Derived from Curcumin and 4-Aminoantipyrine

Kulandaisamy A., Thomas M.

Polish Journal of Chemistry

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2008

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Vol. 82, nr 3

469-480

EN

Neutral complexes of Cu(II), Ni(II), Co(II), VO(II) and Zn(II) have been synthesized from the new Schiff base de rived from curcumin and 4-aminoantipyrine. The structural features of the com plexes have been de ter mined from their microanalytical, magnetic susceptibility, molar conductance, IR, UV-Vis, 1H-NMR, mass and ESR spectral data. All the complexes exhibit square planar geometry while vanadyl complex exists in a square pyramidal geome try. Their magnetic susceptibility measurements and low conductance data provideevidence for the monomeric and non-electrolytic nature of the complexes respectively. Mass, 1H-NMR spectra of the Schiff base and its com plexes suggest that the general formula of the complexes is [ML2]. The redox behaviour of the Cu(II), Ni(II) and VO(II) complexes in MeCN at 300 K was studied by using cyclic voltammetry. The X-band ESR spectra of copper and vanadyl complexes in DMSO solution at 300 K and 77 K were recorded and their salient features were discussed. The antimicrobial activity of the ligand and its complexes against the bacteria Staphylococus aureus, Bacillus subtilis, Klebsiella pneumoniae, Salm nella typhi, Pseud monas aeruginosa and Shigella flexneri are also reported.

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Influence of nickel ions on dielectric and other physical properties of PbO-MoO3-B2O3 glass system

Prasad P.S., Kumar V.R., Raju G.N., Veeraiah N.

Materials Science Poland

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2008

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Vol. 26, No. 3

527--545

EN

PbO–MoO3–B2O3 glasses containing various proportions of NiO (ranging from 0 to 1.0 mol %) have been prepared. A number of methods viz., differential thermal analysis, spectroscopic (IR and UV-Vis optical absorption, and ESR spectra) and dielectric properties (ĺ', tanä, a.c. conductivity óac over a range of frequencies and temperatures) of these glasses has been employed in studies. The results of differential thermal analysis suggest a high glass forming ability for the glass containing 0.6 mol % of NiO. The studies of UV-Vis and IR spectra show that nickel ions occupy both tetrahedral and octahedral positions in the glass network with the dominance of the tetrahedral positions when the concentration of NiO is below 0.6 mol % in the glass matrix. The analysis of the results of studies of dielectric properties reveals that there is an increase in the rigidity and the dielectric breakdown strength of the glass when the concentration of NiO is around 0.6 mol %.

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Synthesis, structural Characterization, Cyclic Voltammetric and Antibecterial Studies of Tetraaza 13-Membered Macrocyclic Copper(II), NIckel(II), Cobalt(II) and Zinc(II) Complexes DErived from the Schiff Base 3-Salicylidene-2,4-di(imino-4'-antipyrinyl)pe

Raman N., Thangaraja C.

Polish Journal of Chemistry

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2005

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Vol. 79 / nr 7

1123-1134

EN

Atetraaza macrocyclic Schiff base (L), synthesized from the Schiff base 3-salicylidene- 2,4-di(imino-4_-antipyrinyl)pentane (3SDAP) and o-phenylenediamine, acts as a tetradentate ligand to form cationic solid complexes with Cu(II), Ni(II), Co(II) and Zn(II) metal salts in ethanol. All the synthesized complexes were characterized by microanalytical data, magnetic susceptibility measurements, IR, UV-Vis, 1H-NMR, 13C-NMR, ESR and mass spectral techniques. The IR and UV-Vis spectral data and magnetic susceptibility values of the complexes suggest that the [CuL]Cl2, [NiL]Cl2, [CoL]Cl2 and [ZnL]Cl2 complexes exhibit square-planar geometry. The electrolytic behaviour and monomeric nature of the chelates were confirmed from their molar conductance data and magnetic susceptibility values respectively. Cyclic voltammetric data of copper complex in DMSO reveal that the unusual oxidation states such as Cu(I) and Cu(0) are stabilized by the ligand system. The cyclic voltammogram of the nickel(II) complex was also recorded in DMSO solution and the salient features are reported. The X-band ESR spectra of the copper complex in DMSO solution at 300 K and 77 K were recorded and their spin Hamiltonian parameters were calculated. The in vitro biological screening effects of the investigated compounds were tested against some microorganisms. The metal complexes have higher activity than the free ligand and the standard.

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Synthesis, Structural Characterization, Redox and Antimicrobial Studies of Schiff Base Copper(II), Nickel(II), Cobalt(II), Manganese(ii), Zinc(II) and Oxovanadium(ii) Complexes derived from benzil and 2-Aminobenzyl Alcohol

Raman N., Kulandaisamy A., Jeyasubramanian K.

Polish Journal of Chemistry

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2002

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Vol. 76 / nr 8

1085-1094

EN

Neutral complexes of Cu(II), Ni(II), Co(II), Mn(II), VO(II) and Zn(II) have been synthesized from the Schiff base derived from benzil and 2-aminobenzyl alcohol. The structural features have been arrived from their microanalytical, IR, UV-Vis, 1H NMR, Mass and ESR spectral data. All of the complexes exhibit square-planar geometry except the Mn(II) and VO(II) complexes. The Mn(II) chelate shows an octahedral environment and the VO(II) chelate exists in a square-pyramidal geometry. The monomeric and non-electrolytic nature of the complexes is evidenced by their magnetic susceptibility and low conductance data. The cyclic voltammogram of copper complex in acetonitrile solution shows two quasi reversible peaks for the Cu(II)/Cu(III) and Cu(II)/Cu(I) couples. The X-band ESR spectra of the Cu(II) and VO(II) complexes in DMSO at 300 and 77 K were recorded and their salient features are reported. The biological activity of the metal chelates against the bacteria Staphylococcus aureus, Bacillus subtilis, Klebsiella pneumoniae, Salmonella typhi, Pseudomonas aeruginosa and Shigella flexneri are also reported. Most of the complexes have higher activity than that of the free Schiff base and the control.

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Synthesis and Characterization of Iron(III), Cobalt(II), Nickel(II) and Copper(II) Complexes of 4-Formylazohydrazoaniline Antipyrine

El-Saied F., Ayad M. I., Issa R. M., Aly S. A.

Polish Journal of Chemistry

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2001

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Vol. 75, nr 6

773-783

EN

4-Formylazohydrazoaniline antipyrine and its iron(III), cobalt(II), nickel(II) and copper( II) complexes have been synthesized and characterized by IR, electronic spectra, molar conductivities, magnetic susceptibilities and ESR. The ligand behaves as a neutral bidentate and tridentate ligand in the hydrazo form or monobasic tridentate ligand in the enol-azo form. Coordination takes place via the carbonyl oxygen of the side chain, azomethine nitrogen atom for bidentate coordination. The carbonyl oxygen of the pyrazolone ring is added for tridentate coordination and enolic oxygen appears in monobasic tridentate coordination.

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Copper(II) Complexes of 4-Azocyanoacetamidoaniline Antipyrine and 4-Azocyanoacetamido-m-toludine Antipyrine

El-Saied F., Ayad M. I., Issa R. M., Aly S. A.

Polish Journal of Chemistry

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2001

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Vol. 75, nr 7

941-947

EN

The synthesis and characterization of copper(II) complexes with 4-azocyanoacetamidoaniline antipyrine (HL1) and 4-azocyanoacetamido-m-toludine antipyrine (HL2) are reported. Elemental analyses, molar conductivities, magnetic moments and spectral (IR, electronic and ESR) studies have been used. The elemental analyses and IR spectra show that the ligands behave as neutral or monobasic bidentate ones, either in the ketoazo or enolazo form. The IR spectra also show that, in the chlorocomplexes (1 and 4), the cyano group is changed to amide (--CO--NH2). Stereochemical structures for the complexes are proposed.

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Synthesis and spectral characterization of Mn(II), Fe(III), Co(II), Ni(II) and Cu(II) complex produced from the template reaction of diacetyloxime

El-Tabl A.S., Kashar T.I.

Polish Journal of Chemistry

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1998

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Vol. 72, nr 3

519-526

EN

A new series of Mn(II), Fe(III), Co(II), Ni(II) and Cu(II) complexes obtained by the template reaction of diacetyloxime and 1,2-diaminopropane with metal ions have been synthesized and characterized by elemental analyses, IR, VIS-UV, electrical conductivity, magnetic moment and ESR measurements. ESR spectrum of Cu(II) complex exhibits an axial type symmetry d(x(2)-y(2)) with covalent bond character. ESR spectrum of Ni(I) at 77K formed by exposing the Ni(II) complex to ionizing radiation, points on d(x(2)-y(2)) ground state. ESR spectrum of Fe(III) complex presents a low spin (57)Fe(I=1/2), d(5), configuration with D(z)(2)) ground state.

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Interaction of nitrobenzene with MgO surface by temperature programmed desorption and ESR spectroscopy

Duński H., Jóźwiak W.K., Paryjczak T., Wysocki S.

Polish Journal of Chemistry

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1998

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Vol. 72, nr 11

2471-2485

EN

The adsorption of nitrobenzene on the surface of magnesium oxide has been studied by TPD and ESR methods. The high temperature activation of MgO reveals the presence of low coordinated oxygen ions (LC), which are the one-electron donor (reducting) sites of MgO surface, resulting in the formation of different nitrobenzene anion radicals. The corner O(2-/3C) and probably the edge O(2-/4C) lattice ions are the source of single electrons to the adsorbed nitrobenzene molecules. Depending on adsorption temperature and surface coverage, there are visible at leastthree forms of NB radicals in ESR spectra with different values of the hyperfine splitting (A(N/II)). These forms differ in thermal stability. The small variations of particular A(N/II) value was attributed to the different chemical environment of the low coordinated adsorption sites on MgO surface.