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41.
Anife Ahmedova Petja Marinova Samuele Ciattini Neyko Stoyanov Michael Springborg Mariana Mitewa 《Structural chemistry》2009,20(1):101-111
The synthesis, structure and spectral properties of a new cinnamoyl derivative of 2-acetyl-1,3-indandione (2AID), p-fluoro-cinnamoyl-1,3-indandione, LH and its metal(II) complexes with Cu(II), Zn(II) and Cd(II), are described. In order to
verify the molecular structure of the free ligand and its metal complexes, model geometries based on the spectroscopic data
were optimized using quantum chemical methods. The experimental spectroscopic data (IR and NMR) of the ligand, LH, complemented
by the calculated ones, show that it exists in the exocyclic enolic form in the gas phase, solution and solid state. Good
quality single crystals of Cd(II) complex were obtained from a DMSO solution and were studied by means of single-crystal X-ray
diffraction. The data show bidentate coordination of the ligand and two DMSO molecules coordinated to the metal centre, thus
forming a complex with octahedral geometry. On the contrary, the spectroscopic data on the amorphous samples indicate a square
planar geometry of the Cu(II) complex and distorted octahedral geometry for Zn(II) and Cd(II) complexes with two water molecules
coordinated to the metal centre. The used quantum chemical method for structure optimization of the transition metal complexes,
B3LYP/LANL2DZ, shows very good agreement with the crystallographic data and, therefore, was also employed for structural determination
for the non-crystalline complexes.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
42.
J. Lorenzzi G. Zoulis M. Marinova O. Kim-Hak J.W. Sun N. Jegenyes H. Peyre F. Cauwet P. Chaudouët M. Soueidan D. Carole J. Camassel E.K. Polychroniadis G. Ferro 《Journal of Crystal Growth》2010,312(23):3443-3450
We report on a comparative investigation of the incorporation of group III, IV and V impurities in 3C–SiC heteroepitaxial layers grown by the vapour–liquid–solid (VLS) mechanism on on-axis α-SiC substrates. To this end, various Si-based melts have been used with addition of Al, Ga, Ge and Sn species. Homoepitaxial α-SiC layers grown using Al-based melts were used for comparison purposed for Al incorporation. Nitrogen incorporation depth profile systematically displays an overshoot at the substrate/epilayer interface for all the layers. Ga and Al incorporations follow the same distribution shape as N whereas this is not the case for the isoelectronic impurities Ge and Sn. This suggests some interaction between Ga/Al and N coming from the high bonding energy between the group III and V elements, which does not exist with Ge and Sn. This is why both incorporate as a cluster. A model of incorporation is proposed taking into account metal-N and metal-C bonding energies together with the solid solubility of the corresponding nitrides. 相似文献
43.
The effect of laser ablation on copper foil irradiated by a short 30 ns laser pulse was investigated by X-ray photoelectron spectroscopy. The laser fluence was varied from 8 to 16.5 J/cm2 and the velocity of the laser beam from 10 to 100 mm/s. This range of laser fluence is characterized by a different intensity of laser ablation. The experiments were done in two kinds of ambient atmosphere: air and argon jet gas.The chemical state and composition of the irradiated copper surface were determined using the modified Auger parameter (α′) and O/Cu intensity ratio. The ablation atmosphere was found to influence the size and chemical state of the copper particles deposited from the vapor plume. During irradiation in air atmosphere the copper nanoparticles react with oxygen and water vapor from the air and are deposited in the form of a CuO and Cu(OH)2 thin film. In argon atmosphere the processed copper surface is oxidized after exposure to air. 相似文献
44.
Anife Ahmedova Vasil Atanasov Petja Marinova Neyko Stoyanov Mariana Mitewa 《Central European Journal of Chemistry》2009,7(3):429-438
New 2-acyl-1,3-indandione derivatives, compounds 1–4, were obtained by condensation of 2-acetyl-1,3-indandione with benzaldehyde,
thiophene-2-aldehyde, thiophene-3-aldehyde and furane-2-aldehyde, respectively. The structures of the newly synthesized 2-substituted
1,3-indandiones were characterized by means of spectroscopic methods (FT-IR, 1H and 13C NMR, UV-Vis and MS). Based on the obtained results it is suggested that the compounds exist in the exocyclic enolic form.
Mass spectral fragmentation paths are also proposed. In order to verify the possibility for tautomerization processes of the
newly synthesized compounds their absorption spectra were recorded in various solvents. Furthermore, the complexation properties
of the compounds with metal(II) ions were also studied. A series of non-charged complexes with Cu(II), Cd(II), Zn(II), Co(II)
and Ni(II) was isolated and analyzed by elemental analyses and IR. The paramagnetic Cu(II) complexes were studied by EPR and
distorted, flattened tetrahedral structures are predicted. The other metal complexes show the presence of water molecules,
most probably coordinated to the metal ion, thus forming octahedral geometry. Ultimately, the studied properties of the newly
synthesized compounds, 1–4, suggest that they may find application as extracting agents for metal ions, rather than as optical
sensors.
相似文献
45.
Evelina Marinova 《Nuclear Physics B - Proceedings Supplements》2011,215(1):125-127
46.
Yu. M. Gledenov J. Kvitek S. Marinova Yu. P. Popov J. Rigol V. I. Salatski 《Zeitschrift für Physik A Hadrons and Nuclei》1982,306(1):57-61
TheK-internal conversion coefficient of the 205 keV (7/2+→5/2+) transition in107Cd was determined. From the measured value α K =0.0552±0.0009 and the known value of theE2/M1 mixing ratio δ2 a value of 6.3±1.5 was deduced for the penetration parameterλ. Information derived on effective gyromagnetic ratios in the frame of an extreme single particle model is briefly discussed. 相似文献
47.
Yu.P. Gangrsky V.D. Karaivanov B.N. Markov S.G. Zemlyanoi Tz.T. Kokalova K.P. Marinova E. Stachowska J. Dembczynski J. Ruczkowski B. Arcimowicz 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2000,11(3):341-345
The laser-induced resonance fluorescence in an atomic beam was used in order to measure the hyperfine splitting of the 4f
7 6s
2
and 4f7 6s6p
levels in 151,153,155Eu isotopes. The hfs constants A and B of the unstable 155Eu were determined for the first time: MHz, MHz and MHz. With these data and after corrections for second-order hyperfine structure perturbations the nuclear moments of 155Eu were deduced: n.m. and b. In addition new and more precise values of the hfs constants of the excited state for the stable 151,153Eu were obtained. They are as follows: MHz, MHz and MHz, MHz. The hyperfine anomalies % and % were extracted from the corrected hfs constants.
Received 28 July 1999 and Received in final form 14 January 2000 相似文献
48.
M. Marinova 《光谱学快报》2013,46(3):192-195
ABSTRACT The goal of this work is to study the possibilities for quantitative determination of the number of iron atoms in the mineral core of ferritin by atomic absorption spectroscopy (AAS). Distinctive AAS measurements show iron content between 1000 and 4500 atoms per molecule ferritin.[ 1-6 ] This motivated us to investigate the amount of iron in the horse spleen ferritin with atomic absorption spectroscopy under application of the Bulgarian standard BDS EN 14082/2003 Foodstuffs—Determination of Trace Elements—Determination of Lead, Cadmium, Zinc, Copper, Iron and Chromium by Atomic Absorption Spectrometry (AAS) after Dry Ashing.[ 7 ] We have obtained as a result 1792 atoms in one ferritin molecule. This result is in accordance with previous results, published by leading researchers.[ 4 , 5 ] The investigation of the iron content with AAS under the use of the Bulgarian standard can be a good opportunity to study many other objects of biological interest. 相似文献
49.
50.