摘要:

Copper(II) chromate and dichromate complexes with 2-(2′-pyridyl)imidazole were synthesized and characterized (IR, FIR, UV-VIS-NIR spectroscopy and conductometric data). The coordination of the chromate and dichromate ions has been found which is in accordance with the recently obtained biological results.

ISSN:0038-7010    

DOI:10.1080/00387019808006756

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The mononuclear and dinuclear copper (II) chromate and dichromate complexes with 2-(2′-pyridyl)imidazole were synthesized and characterized. The EPR data and the magnetic studies revealed the dimeric structure for some of the compounds as well as elongated tetragonal and rhombic tetragonal octahedron around copper ion.

ISSN:0038-7010    

DOI:10.1080/00387019808006757

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The theoretically developed Attached Proton Test (APT) and Distortionless Enhancement by Polarization Transfer (DEPT) curves for methane were compared with the corresponding experimentally measured data for13C enriched methane. As expected, in both cases the CH4curves have a similar shape than the corresponding CH2curves and show a minimum intensity when τ =1/2J.In the APT case the CH2curve takes larger values than the CH4 curve except at τ =0, 1/2Jand1/Jvalues where they have the same intensity. In the DEPT experiment, the maximum polarization transfer for CH4takes place at τ =1/6Jand5/6J, while for CH2this happen at τ =1/4Jand3/4J.This fact could be useful to distinguish the CH2and CH4signals using APT and DEPT experiments.

ISSN:0038-7010    

DOI:10.1080/00387019808006758

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

An FTIR method is described and evaluated for the low concentration analysis of volatile anaesthetics (halothane, isoflurane) and nitrous oxide. It has been found that no serious problem occurs in the trace determination of volatile anaesthetics but nitrous oxide introduces lack of sensitivity (<10 ppm) and non linearity problems at lower concentrations (<40 ppm) in the described analysis method.

ISSN:0038-7010    

DOI:10.1080/00387019808006759

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Analysis of H-H n.O.e. effects observed for the adducts on C-13 (10–18) of dehydrocostus lactone and different pyrimidine derivatives shown that H-7 and H-11 protons are in trans position. The NOESY cross peaks analysis and x-ray molecular structure of adduct10are in excellent agreement with the experimental data. Complete assignments of the13C signals of some adducts based on 1D and 2D H and13C NMR techniques are reported.

ISSN:0038-7010    

DOI:10.1080/00387019808006760

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Coordination compounds of Zn(II), Cu(II) and Ni(II) with N-[5-nitro-furfurylidene]-N2-[β-isatin]azine were prepared. Using elemental analysis, atomic absorption (AA), molar conductances, Fourier transform infrared (FTIR), electronic (UV/VIS) spectroscopics methods, their structure were established to be [ZnLCl2].H2O, [CuLCl2].H2O and [NiL2Cl2].2H2O. Spectral studies indicate complexation through nitrogen aiom and oxygen atom of isatin part of ligand. Coordination compounds were tested for antibacterial activity againstStaphylococcus aureus. Enterococcus D. Proteus vulgaris and Escherichia coli.

ISSN:0038-7010    

DOI:10.1080/00387019808006761

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The kinetics of the spontaneous reduction of hexanitrocobaltate(III) ion have been investigated spectrophotometrically (λ=360 nm at 298 K) in ethanol or acetone water mixtures containing 0, 10, 25 and 50 % of organic solvents. The mechanism of this process was expressed by means of two consecutive first-order reactions. Both of the first-order rate constants decrease with the increasing nonaqueous species content. The reduction of hexanitrocobaltate(III) ion in the mixtures was much slower than the corresponding reaction in water.

ISSN:0038-7010    

DOI:10.1080/00387019808006762

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The well known methods of Job's continuous variations and mole-ratio were used for the determination of the compositions of some metal-N,N-diethyl-N′-benzoyl-thiourea complexes chromatographically using HPTLC-densitometry. A different and a simple application of these two methods makes the determination of the composition of metal-ligand complexes possible even when the maximum absorption wavelengths of ligand and complexes are close to each other.

ISSN:0038-7010    

DOI:10.1080/00387019808006763

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The EPR of radicals obtained by electrolytic reduction of some new analogues of the antiprotozoal drug nifurtimox were measured in DMSO and DMF. The electrochemistry of these compounds was studied using cyclic voltammetry AM1 and INDO semiempirical molecular orbital calculations were performed to obtain the optimized geometries and spin distribution, respectively. Density functional theory was used to rationalize the reduction potentials of these compounds.

ISSN:0038-7010    

DOI:10.1080/00387019808006764

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The intensity of the near UV transition of pyridine, pyrazine, and some of their methyl derivatives, is studied on the ground of the Interaction Vector Model (IVM), assuming that this transition is similar to the secondary one of the benzene chromophore.

ISSN:0038-7010    

DOI:10.1080/00387019808006765

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor