共查询到12条相似文献,搜索用时 9 毫秒
1.
M. A. Evsyukova A. N. Kravtsova I. N. Shcherbakov L. D. Popov S. I. Levchenkov Yu. P. Tupolova Ya. V. Zubavichus A. L. Trigub A. V. Soldatov 《Journal of Structural Chemistry》2010,51(6):1075-1080
A copper bromide complex based on benzoin 1′-phthalazinylhydrazone is synthesized. Within density functional theory (OPBE/TZP)
the optimal structural parameters of the complex are determined. X-ray Absorption Near-Edge Structure (XANES) spectra above
the K absorption edge of copper are measured in the copper bromide complex. Theoretical XANES spectra of the K absorption edge of copper are calculated based on the full multiple scattering method and in the full potential of the finite
difference method. Good agreement between the theoretical XANES spectrum and the experimental data is obtained. 相似文献
2.
《Journal of Coordination Chemistry》2012,65(21):3708-3720
Seven coordination compounds based on 1,1′-(1,4-butanediyl)bis(3-carboxyl-2-oxidopyridinium), [CoNa(L)1.5(C2H5OH)3] (1), [Zn(L)(OH)2]?·?4H2O (2), [Co(L)(OH)2]?·?2H2O (3), [Co(L)(H2O)] (4), [Zn(L)(H2O)] (5), [Ni(L)(H2O)] (6), and [Mn(L)(H2O)] (7), have been synthesized and crystal structures have been determined by single-crystal X-ray diffraction. Compound 1 exhibits a 0-D molecular structure. Compound 2 shows a 1-D “Z” chain structure. Neighboring chains are further linked by hydrogen-bonding interactions into a 2-D supramolecular layer. Compound 3 features a 1-D “Z” chain structure. The chains are further extended into a 2-D supramolecular structure by hydrogen-bonding interactions. Compounds 4–7 are isomorphous and display 2-D (44)-SQL networks. These compounds are further characterized by infrared spectra, elemental analyses, and X-ray powder diffraction. The luminescent properties of the compounds were also investigated. 相似文献
3.
W. W. Fu Q. W. Cheng H. Y. Wang F. Z. R. He Y. Liu F. X. Zhang 《Russian Journal of Coordination Chemistry》2017,43(8):547-558
Four homoleptic copper(II) complexes, [Cu(Meophtpy)2](ClO4)2 (Meophtpy = 4′-(4-methoxylphenyl)- 2,2′:6′,2″-terpyridine) (I), [Cu(Meophtpy)2](ClO4)2 · 2H2O (II), [Cu2(m-Clphtpy)4](ClO4)4 (m-ClPhtpy = 4′-(3-chlorophenyl)-2,2′:6′,2″-terpyridine) (III), and [Cu2(m-ClPhtpy)4](ClO4)4 (IV) have been synthesized by hydrothermal methods and characterized by IR, elemental analysis and single crystal X-ray diffraction (CIF files CCDC nos. 963375 (I), 885457 (II), 963377 (III), and 963376 (IV)). Complex II is a polymorph of I and complex IV is a polymorph of III. All these complexes are obtained with 95% ethanol solution or 50% ethanol solution and the solvent control on the crystallization are obviously found. In all complexes, the face-to-face interactions between pyridyl rings or phenyl rings facilitate the construction of 3D network in the crystal in addition to hydrogen bonds. The fluorescence properties of these complexes have been investigated. 相似文献
4.
Júlio C. Souza Carlos H. F. B. Souza Claúdio Homero F. Silva Maria Elisa S. R. Silva Ricardo G. Sousa Roberto F. S. Freitas 《Macromolecular Symposia》2012,319(1):150-160
Summary: In the present work, a methodology of synthesis and characterization of the monomer 2,2′ diallylbisphenol-A (ABFA) was developed, aiming at getting a precursor, with adequate purity, for obtaining cross-linked membranes based on sulphonated poly(arylene ether sulphone)s. The monomer synthesis involved the synthesis of 2,2′ bis(4-allyloxiphenyl)propane (Bisphenol-A, diallyl ether - BFAAE), from Bisphenol-A (BFA), followed by Claisen rearrangement of BFAAE, for the production of the target compound 2,2′ diallylbisphenol-A (ABFA). All the compounds, reagent BFA and obtained products, intermediate product BFAAE and final product ABFA, were characterized by FTIR (Fourier Transform infrared spectroscopy), TGA (Thermo-gravimetric analysis) and HPLC (High-performance liquid chromatography). The compound BFAAE was obtained with a yield of 94.5% and a purity of 97.3%, the latter characterized by TGA and by HPLC. The structure of the product was confirmed by FTIR. The thermal Claisen rearrangement process was conducted by using Differential Scanning Calorimetry (DSC) technique, from a factorial experiment planning, with two factors and three levels, with temperature and time being the variables. The above cited techniques were used for monitoring the Claisen rearrangement and for the characterization of the final product. The best results yield ABFA purity between 85 and 90%, approximately, for 220 °C/60min, 230 °C/30min and 210 °C/90min conditions. The obtained results suggest that, in the studied range, polymerization and degradation of the monomer ABFA occur, simultaneously to its formation. 相似文献
5.
Jürgen Gäb Marco Melzer Kai Kehe Stefan Wellert Thomas Hellweg Marc-Michael Blum 《Analytical and bioanalytical chemistry》2010,396(3):1213-1221
The enzyme diisopropyl fluorophosphatase (DFPase, EC 3.1.8.2) from the squid Loligo vulgaris effectively catalyzes the hydrolysis of diisopropyl fluorophosphate (DFP) and a number of organophosphorus nerve agents,
including sarin, soman, cyclosarin, and tabun. Until now, determination of kinetic data has been achieved by use of techniques
such as pH-stat titration, ion-selective electrodes, and a recently introduced method based on in situ Fourier-transform infrared
(FTIR) spectroscopy. We report the use of 1D 1H–31P HSQC NMR spectroscopy as a new method for real-time quantification of the hydrolysis of toxic organophosphonates by DFPase.
The method is demonstrated for the agents sarin (GB), soman (GD), and cyclosarin (GD) but can also be used for V-type nerve
agents, for example VX. Besides buffered aqueous solutions the method was used to determine enzymatic activities in a biodiesel-based
bicontinuous microemulsion that serves as an example of complex decontamination media, for which other established techniques
often fail. The method is non-invasive and requires only limited manual handling of small volumes of liquid (700 μL), which
adds to work safety when handling highly toxic organophosphorus compounds. Limits of detection are slightly below 100 μmol
L−1 on a 400 MHz spectrometer with 16 FIDs added for a single time frame. The method is not restricted to DFPase but can be used
with other phosphotriesterases, for example paraxonase (PON), and even reactive chemicals, for example oximes and other nucleophiles,
as long as the reaction components are compatible with the NMR experiment.
相似文献
6.
Fernando de la Peña Moreno Gracia Patricia BlanchGema Flores Maria Luisa Ruiz del Castillo 《Journal of chromatography. A》2010,1217(7):1083-1088
A method based on the use of the through oven transfer adsorption–desorption (TOTAD) interface in on-line coupling between reversed phase liquid chromatography and gas chromatography (RPLC–GC) for the determination of chiral volatile compounds was developed. In particular, the method was applied to the study of the influence of methyl jasmonate (MJ) treatment on the production and enantiomeric composition of selected aroma compounds in strawberry. The compounds studied were ethyl 2-methylbutanoate, linalool and 4-hydroxy-2,5-dimethyl-3(2H)-furanone (i.e. furaneol), which were examined on days 3, 6 and 9 after treatment. The method developed resulted in relative standard deviations (RSDs) of 21.6%, 8.1% and 9.8% and limits of detection (LD) of 0.04, 0.07 and 0.02 mg/l for ethyl 2-methylbutanoate, linalool and furaneol, respectively. The application of the RPLC–TOTAD–GC method allowed higher levels of ethyl 2-methylbutanoate, linalool and furaneol to be detected, particularly after 9 days of treatment. Besides, MJ demonstrated to affect the enantiomeric distribution of ethyl 2-methylbutanoate. On the contrary, the enantiomeric composition of linalool and furaneol kept constant in both control and MJ-treated strawberries throughout the study. These results are discussed. 相似文献
7.
《Tetrahedron: Asymmetry》1998,9(7):1223-1229
A new chiral lithium amide has been designed starting from (S)-proline. This new chiral lithium amide has been used for asymmetric deprotonation/ring opening of cyclohexene oxide to give (S)-2-cyclohexen-1-ol in 88% yield and 78% enantiomeric excess. NMR studies of the lithium amide and the ligand–substrate complex are also presented. 相似文献
8.
Saskia Menzel Konstantinos D. Demadis Christoph Janiak 《Phosphorus, sulfur, and silicon and the related elements》2020,195(10):830-835
AbstractThe fully deprotonated anion of 1,3,5-benzene-triphosphonic acid 1,3,5-C6H3[PO32?]3 gives rise to deceptively simple 1H and 31P NMR spectra due to a corresponding [AX]3 spin system. The 13C{1H} NMR spectrum reveals two 13C isotopomers which are identified via AXX′2 systems. Results from analysis and iteration are described. 相似文献
9.
N. A. Sanina S. M. Aldoshin G. V. Shilov E. V. Kurganova E. A. Yurieva N. A. Voloshin V. I. Minkin V. A. Nadtochenko R. B. Morgunov 《Russian Chemical Bulletin》2008,57(7):1451-1460
Paramagnetic (tris)oxalates with the composition (SP)3M(C2O4)3·4H2O (M = Cr (2), Mn (3), Fe (4), and Co (5)) were synthesized for the first time based on the spiropyran salt SP+Br− (1) with the SP+ cation containing the pyridine ring in the aliphatic chain of the benzopyran moiety, which was also prepared in the present
study. According to X-ray diffraction data, the SP+ cations in the starting salt 1 are close-packed thus hindering photochromic transformations. The spin for paramagnet 4 is 5/2, which corresponds to the FeIII atom in the high-spin state, the spin of the system remaining unchanged under UV irradiation. In complex 3, a crossover from ferromagnetic to antiferromagnetic correlations was observed after the replacement of the inorganic cation
with the organic spiropyran cation.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1424–1432, July, 2008. 相似文献
10.
11.
T. A. Rodina I. A. Lutsenko A. V. Gerasimenko A. V. Ivanov 《Russian Journal of Coordination Chemistry》2009,35(7):534-540
The complex bis(O,O′-diisobutyl dithiophosphato)platinum(II) (I) was obtained and characterized by solid-state 13C, 31P, and 195Pt CP/MAS NMR spectroscopy. In complex I, the dithiophosphate fragments are structurally equivalent with a predominantly orthorhombic tensor of the 31P chemical shift (η = 0.73). The tensor of the 195Pt chemical shift approximates to an axially symmetric one (for δzz> δxx and δyy), which suggests the existence of square chromophores [PtS4], as in cooperite (natural PtS). The crystal and molecular structures of complex I were determined from X-ray diffraction data. The Pt atom coordinates two Dtph ligands in a S,S′-anisobidentate fashion (the Pt-S bonds are nonequivalent: 2.315 and 2.329 Å) to form two four-membered chelate rings [PtS2P] with platinum as a spiro atom. The P-S bond length (1.997 and 1.986 Å), which is intermediate between the idealized lengths of the single and double phosphorus-sulfur bonds, suggests the delocalization of the π-electron density in the structural fragments PS2. In complex I, the electron shielding of the platinum nucleus in the direction perpendicular to the plane of the chromophore [PtS4] was found to be noticeably higher than that in cooperite. The thermal properties of complex I were examined by combined DSC-TG thermal analysis. The intermediate product of the thermolysis of complex I was platinum(II) dithiometaphosphate [Pt(S2PO)2] and the final thermolysis product was PtS. 相似文献
12.
Marcelo O. Santiago Alzir A. Batista Marcio P. de Araújo Claudio L. Donnici Icaro de S. Moreira Eduardo E. Castellano Javier Ellena Sauli dos Santos Jr Salete L. Queiroz 《Transition Metal Chemistry》2005,30(2):170-175
A series of cis-{RuCl2(PPh3)2[4,4-(X)2-2,2-bipy]} [cis-chlorines; X=-H, -Me, -SMe, and (-Cl,-Me)] complexes have had their structures determined by single crystal X-ray diffraction. The geometry of these complexes, also determined in CH2Cl2 solution by 31P{1H}-n.m.r. spectroscopy, showed that the chemical shifts for the phosphorus atoms are slightly dependent on the pKa of the 4,4-(-X)2-2,2-bipy ligands. 相似文献