排序方式: 共有28条查询结果,搜索用时 15 毫秒
1.
Soran Loredana Coman Virginia Soran Albert Silvestru Cristian 《Central European Journal of Chemistry》2004,2(4):563-572
2-(Diethylaminomethyl)phenyl bromide and 1,3-bis(dimethylaminomethyl)-benzene, useful ligands for the synthesis of hypervalent
organometallic compounds, were prepared and characterized by NMR (1H, 13C, 2D experiments) spectroscopy. Their synthesis was monitored by the HPLC method. The compounds were eluted on a Nucleosil
120 Si column (5 μm, 25×0.4 cm) with n-hexane at room temperature using a 1.0 ml/min flow-rate. The maximum values of absorbance for the studied compounds, excepting
the diethylamine, were located in a narrow range around 212 nm, the wavelength used for their UV detection. The diethylamine
was detected at 190 nm. The calibration curves are straight lines with correlation factors r>0.995. The HPLC data are in good
agreement with those provided by NMR spectroscopy. 相似文献
2.
Bros Ildiko Soran Maria-Loredana Briciu Rodica Domnica Cobzac Simona Codruta 《平面色谱法杂志一现代薄层色谱法》2009,22(1):25-28
JPC – Journal of Planar Chromatography – Modern TLC - A study of quantitative analysis of some flavonoids in Satureja hortensis L. extracts is presented. The HPTLC analyses were... 相似文献
3.
JPC – Journal of Planar Chromatography – Modern TLC - The separation and quantitative analysis of thymol in Satureja hortensis L. extracts is reported. The extracts were obtained by... 相似文献
4.
Hawraz Ibrahim M. Amin Faiq H. S. Hussain Soran K. Najmaldin Zaw Min Thu Mohammed Farhad Ibrahim Gianluca Gilardoni Giovanni Vidari 《Molecules (Basel, Switzerland)》2021,26(2)
A dozen Iris species (Iridaceae) are considered traditional remedies in Kurdistan, especially for treating inflammations. Phytochemical studies are still scarce. The information reported in the literature about Iris species growing in Kurdistan has been summarized in the first part of this paper, although, except for Iris persica, investigations have been performed on vegetal samples collected in countries different from Kurdistan. In the second part of the work, we have investigated, for the first time, the contents of the methanolic extracts of Iris postii aerial parts and rhizomes that were collected in Kurdistan. Both extracts exhibited a significant dose-dependent free radical scavenging and total antioxidant activities, comparable to those of ascorbic acid. Medium-pressure liquid chromatographic separations of the two extracts afforded l-tryptophan, androsin, isovitexin, swertisin, and 2″-O-α-l-rhamnopyranosyl swertisin from the aerial parts, whereas ε-viniferin, trans-resveratrol 3,4′-O-di-β-d-glucopyranoside, and isotectorigenin were isolated from the rhizomes. This is the first finding of the last three metabolites from an Iris species. The various remarkable biological activities of isolated compounds scientifically sustain the traditional use of I. postii as a medicinal plant. 相似文献
5.
H. J. Breunig L. Balázs N. Philipp A. Soran C. Silvestru 《Phosphorus, sulfur, and silicon and the related elements》2013,188(4-5):853-857
The homocycles (RBi)n (n = 3–5) react with MeC5 H4Mn(CO)2(thf) (thf = tetrahydrofuran) or Fe2(CO)9 to give Bi2[Mn(CO)2MeC5 H4]3 (1) or Bi2Fe3(CO)9 (3). Reaction of R4Bi2 (R = Me3SiCH2) with Fe2(CO)9 in toluene gives R2Bi2Fe2(CO)8 (4) and R4Bi2Fe(CO)4 (5). The heterocycles (RBiS)2(R = 2-(Me2NCH2)C6 H4 (6), 2, 6-(Me2NCH2)2 C6 H4 (7) are formed by reaction of the corresponding dihalides RBiCl2 with Na2S. The reaction of (RBiS)2(R = 2-(Me2NCH2)C6 H4) with W(CO)5(thf) leads to (RBiS)2[W(CO)5]2 (8). 相似文献
6.
Performance of density‐functional tight‐binding models in describing hydrogen‐bonded anionic‐water clusters 下载免费PDF全文
Soran Jahangiri Lemin Cai Gilles H. Peslherbe 《Journal of computational chemistry》2014,35(23):1707-1715
Density‐functional tight‐binding (DFTB) models are computationally efficient approximations to density‐functional theory that have been shown to predict reliable structural and energetic properties for various systems. In this work, the reliability and accuracy of the self‐consistent‐charge DFTB model and its recent extension(s) in predicting the structures, binding energies, charge distributions, and vibrational frequencies of small water clusters containing polyatomic anions of the Hofmeister series (carbonate, sulfate, hydrogen phosphate, acetate, nitrate, perchlorate, and thiocyanate) have been carefully and systematically evaluated on the basis of high‐level ab initio quantum‐chemistry [MP2/aug‐cc‐pVTZ and CCSD(T)/aug‐cc‐pVQZ] reference data. Comparison with available experimental data has also been made for further validation. The self‐consistent‐charge DFTB model, and even more so its recent extensions, are shown to properly account for the structural properties, energetics, intermolecular polarization, and spectral signature of hydrogen‐bonding in anionic water clusters at a fraction of the computational cost of ab initio quantum‐chemistry methods. This makes DFTB models candidates of choice for investigating much larger systems such as seeded water droplets, their structural properties, formation thermodynamics, and infrared spectra. © 2014 Wiley Periodicals, Inc. 相似文献
7.
Breunig HJ Königsmann L Lork E Nema M Philipp N Silvestru C Soran A Varga RA Wagner R 《Dalton transactions (Cambridge, England : 2003)》2008,(14):1831-1842
R2BiOH (1) [R = 2-(Me2NCH2)C6H4] and (R2Bi)2O (2) are formed by hydrolysis of R2BiCl with KOH. Single crystals of were obtained by air oxidation of (R2Bi)2. The reaction of R2BiCl and Na2CO3 leads to (R2Bi)2CO3 (3). 3 is also formed by the absorption of CO2 from the air in solutions of 1 or 2 in diethyl ether or toluene. (R2Bi)2S (4) is obtained from R2BiCl and Na2S or from (R2Bi)2 and S8. Exchange reactions between R2BiCl and KBr or NaI give R2BiX [X = Br (5), I (6)]. The reaction of RBiCl2 (7) with Na2S and [W(CO)5(THF)] gives cyclo-(RBiS)2[W(CO)5]2 (8). cyclo-(R'BiS)2 (9) [R' = 2,6-(Me2NCH2)2C6H3] is formed by reaction of R'BiCl2 and Na2S. The structures of were determined by single-crystal X-ray diffraction. 相似文献
8.
A. P. Rija A. Nicolescu A. Soran E. B. Coropceanu I. I. Bulhac O. A. Bologa C. Deleanu P. N. Bourosh 《Russian Journal of Coordination Chemistry》2011,37(10):757-765
The complexes [Co(DH)2(Seu)
y
(Se-Seu)
z
]2X · mSolv (DH is the dimethylglyoxime monoanion, Seu is selenourea, and X is [TiF6]2−, [ZrF6]2−) were obtained from the system CoX · 6H2O-DH2-Seu in DMF-MeOH or MeOH-H2O and examined by UV, IR, and NMR spectroscopy and X-ray diffraction. Unexpectedly, the ligand Se-Seu (the oxidized form of
selenourea) was detected on the axial coordinate, partially replacing selenourea. The complexes were formulated as [Co(DH)2(Seu)1.75(Se-Seu)0.25]2[TiF6] · H2O (I) and [Co(DH)2(Seu)(Se-Seu)]2[ZrF6] · 3H2O (II). The complex cations in I and II have trans-octahedral structures. Their crystal structures are made up of the complex Co3+ cations and the outer-sphere MF62− anions (M = Ti(IV) (I) and Zr(IV) (II)) held together by electrostatic interactions and hydrogen bonds; water of crystallization is also involved in hydrogen bonding. 相似文献
9.
JPC – Journal of Planar Chromatography – Modern TLC - The aim of the present work was to establish a proper high-performance thin-layer chromatographic (HPTLC) method for the... 相似文献
10.
Ocsana Opriş Maria-Loredana Soran Virginia Coman Florina Copaciu Dumitru Ristoiu 《Central European Journal of Chemistry》2013,11(8):1343-1351
This study is focused on the determination of some important antibiotics from different classes in waste water samples using solid phase extraction followed by high performance liquid chromatography with two detectors, diode array and mass spectrometer in positive ionisation mode. The investigated antibiotics include three penicillins (amoxicillin, ampicillin, penicillin G), two cephalosporins (ceftazidime, ceftriaxone), and two tetracyclines (tetracycline, doxycycline). The studied antibiotics were extracted from waste water samples using hydrophilic-lipophilic balanced cartridges. The extraction of antibiotics from water matrices was tested at several pH values. The best recoveries were obtained at pH 3 and 7 respectively. Depending on the nature of antibiotic, the limits of detection and quantification were obtained in the range of 0.07–0.92 µg mL?1 and 0.21–2.77 µg mL?1 respectively. Influent and effluent waste water samples were collected from a Waste Water Treatment Plant from Romania in order to detect the studied antibiotics. The antibiotics detected in the influent waste water samples were ceftriaxone (334 µg L?1), tetracycline (146 µg L?1) and doxycycline (110 µg L?1). In effluent waste water samples no target antibiotics were detected. 相似文献