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1.
Mavroudis A Demertzis 《Analytica chimica acta》2004,505(1):73-76
An efficient, more sensitive and accurate spectrophotometric process is possible and can be used to obtain qualitative or quantitative results for analytes at limiting concentrations lower than usual. Transmission measurements (incident light power, P0, or transmitted, P) are performed with a fluorescence spectrometer. One cell only is used to measure standards or unknown solutions, placed between the standard holder cuvette and the emission monochromator of the instrument. The source of the radiant power (P0) is not the xenon lamp but the fluorescence or scattered radiation from the holder cuvette filled with an appropriate solution. The analyte concentration is found from a calibration graph, based upon Beer’s law or the approximate formula P0−P=2.303P0εbc, which is valid for dilute solutions. Determination of iron in a reference material, using 1,10-phenanthroline as the chromogenic reagent, was chosen as an example to demonstrate the suitability of the proposed method and clarify several important statistical questions. Also discussed is why and to what extent molecular fluorescence methods are more sensitive than molecular absorption methods. 相似文献
2.
Kourkoumelis N Demertzis MA Kovala-Demertzi D Koutsodimou A Moukarika A 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2004,60(10):2253-2259
The reactions of the potent and widely used anti-inflammatory drug diclofenac, HL, with diorganotin(IV) oxides were studied. The dimeric tetraorganodistannoxane complexes [Me(2)LSnOSnLMe(2)](2), [Bu(2)LSnOSnLBu(2)](2), [Ph(2)LSnOSnLPh(2)](2) and the dibutyltin complex [Bu(2)SnL(2)], have been prepared and structurally characterized in the solid state by means of vibrational and 119Sn M?ssbauer spectroscopy. Determination of lattice dynamics by temperature-dependent 119Sn M?ssbauer spectroscopy. From the variable-temperature M?ssbauer effect, the Debye temperature was determined. The complexes have been characterized in solution by NMR (1H and 13C) spectroscopy. Vibrational, M?ssbauer, and NMR data are discussed in terms of the proposed structures. 相似文献
3.
Kovala-Demertzi Dimitra Demertzis Mavroudis Yadav Paras Nath Castiñeiras Alfonso West 《Transition Metal Chemistry》1999,24(6):642-647
The synthesis, as well as spectral and structural characterization, of (2-benzoylpyridine-N(4)-methyl-N(4)-phenylthiosemicarbazonato)chloropalladium(II), [Pd(Bz4MePh)Cl], is described. The unit cell contains two crystallographically independent molecules [Pd(1)(Bz4MePh)Cl], (1), and [Pd(2)(Bz4MePh)Cl], (2), stabilized by intra- and intermolecular hydrogen bonding. The distance between the Pd(1) and Pd(2) centres is 3.5038(11) Å. The spectroscopic techniques used in this study are the following: u.v.-visible, i.r. and 1H n.m.r. The protonation constants, determined spectrophotometrically, of the uncoordinated HBz4MePh are pKa1 = 10.82 ± 0.03 and pKa2 = 4.09 ± 0.02. 相似文献
4.
D. Skrzypek B. Szymanska Joanna Wiecek Mavroudis A. Demertzis 《Journal of Physics and Chemistry of Solids》2006,67(12):2550-2558
The interaction of iron (III) with pipemidic acid, Hpipem, afforded the complex [Fe (pipem) (HO)2 (H2O)]2. The new complex has been characterised by elemental analyses, infra-red, EPR and XPS spectroscopies. The monoanion, pipem, exhibits O, O ligation through the carbonyl and carboxylato oxygen atoms. Six coordinate dimer distorted octahedral configuration has been proposed for [Fe (pipem) (HO)2 (H2O)]2. 相似文献
5.
Dimitra Kovala‐Demertzi Vaso Dokorou Zbigniew Ciunik Nikolaos Kourkoumelis Mavroudis A. Demertzis 《应用有机金属化学》2002,16(7):360-368
The triphenyltin adduct of mefenamic acid, [SnPh3L] ( 1 ), the monophenyltin complex [PhSnOL] n ( 2 ), and the dibutyltin complex [SnBu2L2] (3), where HL is 2‐[bis(2,3‐dimethylphenyl)amino]benzoic acid (mefenamic acid), have been prepared and structurally characterized by means of vibrational, 1H and 13C NMR spectroscopies. The crystal structure of 1 has been determined by X‐ray crystallography. X‐ray analysis revealed a pseudo‐pentacoordinated structure containing Ph3Sn coordinated to the carboxylato group. The structural distortion is a displacement from the tetrahedron toward the trigonal bipyramid. Significant C? H–π interactions and intramolecular hydrogen bonds stabilize the structure 1. The polar imino hydrogen atom participates in intramolecular hydrogen bonds. Complex 1 is self‐assembled via C? H–π and stacking interactions. Vibrational and NMR data are discussed in terms of the crystal structure and the proposed structures for 1–3. Compounds 1 and 3 were tested for antimycobacterial activity against Mycobacterium tuberculosis H37Rv. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
6.
Dimitra Kovala‐Demertzi Aglaia Koutsodimou Angeliki Galani Sotiris K. Hadjikakou Mavroudis A. Demertzis Marianna Xanthopoulou John R. Miller Christopher S. Frampton 《应用有机金属化学》2004,18(9):501-502
The crystal structure of complex [Ph2Sn(Hpir)2 ·CH3CN] shows for the first time chelation to a metal atom of piroxicam through the keto‐enolate oxygen atoms. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
7.
Szymańska B Skrzypek D Kovala-Demertzi D Staninska M Demertzis MA 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2006,63(3):518-523
The interaction of copper(II) and manganese(II) with pipemidic acid, Hpipem, afforded the complexes [Cu(pipem)(2)(H(2)O)] x 2H(2)O, 1 and [Mn(pipem)(2)(H(2)O)], 2. The new complexes have been characterised by elemental analyses, infrared, UV-vis and X-band EPR spectroscopy in the temperature range from 4 to 300 K. The monoanion, pipem, exhibits O,O ligation through the carbonyl and carboxylato oxygen atoms. Five coordinate square-pyramid configuration has been proposed for 1 and 2, and the fifth apical position is occupied by a coordinated water molecule. 相似文献
8.
Dimitra Kovala-Demertzi Alexandros Alexandratos Athanassios Papageorgiou Paras Nath Yadav Panagiotis Dalezis Mavroudis A. Demertzis 《Polyhedron》2008
The present paper includes synthesis and spectral characterization of the novel prepared palladium(II) and zinc(II) complexes with 2-formyl pyridine N(4)-1-(2-pyridyl)-piperazinyl thiosemicarbazone, HFo4Npypipe, 1 and the 2-acetyl pyridine N(4)-1-(2-pyridyl)-piperazinyl thiosemicarbazone, HAc4Npypipe, 2. The Pd(II) complexes [PdCl(Fo4Npypipe)], 3, [PdCl(Ac4Npypipe)], 4 and the Zn(II) complexes [ZnCl2(Fo4Npypipe)], 5 and [ZnCl2(Ac4Npypipe)], 6 have been characterized by elemental analyses and spectroscopic studies. The crystal structure of the complexes [PdCl(Fo4Npippy)], 3 and [PdCl(Ac4Npippy)], 4, have been solved by single-crystal X-ray diffraction. The electronic, IR, UV/Vis, and NMR spectroscopic data of the complexes are reported. The results of the cytotoxic activity of 1–6 have been evaluated in vitro against the cells of three human cancer cell lines: MCF-7, T24, A-549 and a mouse L-929 (a fibroblast-like cell line cloned from strain L). For selected compounds 2 and 6 the acute toxicity and antitumor activity were evaluated on leukemia P388-bearing mice. The Zn(II) compounds 5 and 6 are considered as agents with potential antitumor activity, and can therefore be candidates for further stages of screening in vitro and/or in vivo. 相似文献
9.
Dimitra Kovala‐Demertzi Vaso Dokorou Rafal Kruszynski Joanna Wiecek Tadeusz J. Bartczak Mavroudis A. Demertzis 《无机化学与普通化学杂志》2005,631(12):2481-2484
The novel symmetric dimeric tetraorganodistannoxane [(Me2Sn)4(DCPA)2)O2(OH)2] ( 2 ) and [(Me2Sn)4(DCPA)2)O2(OC2H5)2] ( 3 ) where HDCPA is 2‐(2,3‐dichloroanilino)benzoic acid ( 1 ) have been prepared. The crystal structure of 3 has been determined by X‐ray crystallography. Three distannoxane rings are present to the centrosymmetric dimeric tetraorganodistannoxane by virtue of μ3‐oxo form the central R4Sn2O2 core with a planar Sn2O2 ring, resulting in a ladder type structural motif. Five‐coordinated tin atoms are present in the distannoxane dimer. The ligands act as monodentate agents, thus rendering the tin atom five‐coordinated. Significant π → π stacking interactions and intramolecular hydrogen bonds stabilize the structure 3 . The polar imino hydrogen atom participates in intramolecular hydrogen bonds. The formation of the dimeric distannoxanes 2 and 3 represent a ladder‐type carboxylates in which the insertion of a μ2‐OH or a μ2‐OC2H5 group occurs. This unusual result can be interpreted in terms of a competition between the strength different donors, in which the –OH or the –OC2H5 groups show higher donor capacity than the carboxylato group of DCPA. 相似文献
10.
Calcium (0–50 μM) is determined by measuring the fluorescence of its calcein complexes in strongly alkaline solutions. The effects of alkali metal complexation are described, and the nature of the calcium complexes is investigated. The method is applied to serum. 相似文献