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51.
Square planar mixed ligand complexes of the type [CuLL′] where L = 5-chlorosalicylaldehyde and L′ = acetoacetanilide, have
been synthesized on treatment with ammonia. Amine exchange of the above Schiff base complexes has been carried out on treatment
with different amines. The reaction with ethanol amine is quite interesting compared to other amines. It reacts with 5-chlorosalicylaldehyde
to form a Schiff base, while the β-diketone part is removed in the complex formation. All the complexes were characterized
by elemental analysis, spectral studies, magnetic measurement, TLC, and conductane. 相似文献
52.
含Cu复合氧化物对NO和CO吸附和活化的TPSR研究 总被引:2,自引:2,他引:2
利用MS-TPD法并结合XRD、化学分析等对催化剂进行了表征,探讨了K2NiF4结构La2-x(Sr,Th)xCuO4±λ系催化剂中三个典型样品LaSrCuO4、La2CuO4和La1.7Th0.3CuO4对NO、CO及CO+NO等小分子的吸附性能和活化规律。结果表明:NO吸附量的大小与催化剂中氧空位含量有关,吸附强度和脱附峰种类与金属离子氧化态有关。CO在氧缺陷复合氧化物催化剂上的吸附是首先变为碳酸根,并在高温以CO2物种脱出.在NO和CO的共吸附过程中,有关NO的吸、脱性能与单独NO-TPD中NO的吸脱附规律相似,表明NO在NO+CO共吸附的竞争吸附过程中,优先吸附起决定作用,而受CO的影响较小.NO的吸附是NO活化分解的必要条件. 相似文献
53.
A.I. Baranov L. Kloo R.A. Lunin B.A. Popovkin 《Journal of solid state chemistry》2004,177(10):3616-3625
A systematic search for mixed low-valence, nickel-tin chalcogenides performed by establishing phase relations in the parts of Ni-Sn-Se and Ni-Sn-Te ternary systems resulted in the discovery of two new compounds, Ni5.62SnSe2 and Ni5.78SnTe2. Single crystals of both compounds were prepared by chemical transport with iodine and crystal structures were determined by single crystal X-ray investigation. The ED patterns for Ni5.78SnTe2 showed the presence of satellite reflections, which indicate a modulated structure with q≈0.4a*. Average crystal structures of both compounds were determined to be of tetragonal symmetry (Sp.gr. I4/mmm, Z=2) with a=3.6890(8) Å, c=18.648(3) Å, Rw=0.0716 and a=3.7680(5) Å, c=19.419(4) Å, Rw=0.0832, correspondingly, and are isostructural to known Ni5.72SbSe2 and Ni5.66SbTe2. Measurements were carried out for both compounds with respect to thermal, electrical and magnetic properties. Ab initio band structure calculations were also performed to take a first glance into the electronic structure of such type compounds. The anisotropy of their band structure was found. Physical property measurements showed both compounds to be the anisotropic metallic conductors and paramagnetics. Calculated difference charge density maps revealed pairwise covalent and multicenter metallic nature of the d-metal—chalcogen and d-metal—p-metal interactions, respectively. 相似文献
54.
Majid M. Heravi Khadijeh Bakhtiari Negar M. Javadi Hossein A. Oskooie Fatemeh F. Bamoharram 《Monatshefte für Chemie / Chemical Monthly》2007,138(5):445-447
Summary. Acetylation of various alcohols and benzyl amine was tested in the presence of H6[PMo9V3O40], a mixed addenda heteropolyacid, in ethyl acetate under reflux condition. Phenols and anilines are not affected under the
reaction conditions. Selective transestrification of alcohols can be achieved in the presence of phenol and aniline derivatives
using this method. 相似文献
55.
The charge transfer (CT) band maximum of N-alkyl pyridinium iodide (NAPI) has been studied as a function of the composition of binary mixed dipolar aprotic solvents. The deviation from linearity of the energy maximum (E12) and the mole fraction (of a component solvent) plot is explained as due to a preferential solvation by the more polar cosolvent in the binary mixture. The extent of preferential solvation has been observed to vary with the composition, the maximum being towards the less-polar end. The role of hydrogen bond donating ability of a solvent in preferential solvation is discussed. 相似文献
56.
57.
Sophie Guillard 《Tetrahedron》2006,62(24):5608-5616
This work describes advances in the study of the internal condensation of ammonium salts of N-acylsulfonamides. N-Acyltrifluoromethanesulfonamides show considerable advantages over the non fluorinated analogues by virtue of their higher reactivity and acidity. The reaction chemoselectivity has been investigated using a wide range of amines. The sensitivity of the reaction to steric and electronic effects confirms the potential application of these reagents in chemoselective acylation of polyamines. 相似文献
58.
《Electroanalysis》2006,18(8):814-822
Holm oak (Quercus ilex) is the dominant tree growing on serpentine soils of northeast Portugal, characterized by elevated soil concentrations of Ni and Mg, combined with low Ca concentrations. Apparently Q. ilex does not suffer from excessive concentrations of Ni in the soil. In this work we report a complexation study of nickel by the relevant ligands present in xylem sap: histidine, aspartic acid, oxalic and citric acids, at 0.10 M ionic strength and pH 5.5. Single and mixed complexes were characterized. To validate the proposed complexation model, diluted solutions of Q. ilex xylem sap were titrated with nickel. All studies were done using square‐wave voltammetry (SWV) at a hanging mercury drop electrode. Due to the dynamic nature of SWV, it is possible to obtain the conditional stability constants of the complexes formed but also to have knowledge on the kinetics of the interconversion of the species present. 相似文献
59.
新型笼状同多钒酸盐[Ni(1,10′-phen)3]2·[V2ⅣV8ⅤO26]的水热合成和晶体结构 总被引:3,自引:0,他引:3
尽管多金属氧酸盐(POMs)的研究已有180多年的历史, 但大量的POMs结构在最近几十年才被陆续解析出来[1~4]. 相似文献
60.
Using the mixture of cetyltrimethylammonium bromide (CTAB) and p‐Octyl polyethylene glycol phenyl ether (OP‐10) as templates, siliceous MCM‐48 materials can be synthesized with low molar ratio of CTAB to silica (0.139:1) and low concentration of mixed surfactants (ca.5%) and within a wide range of OP‐10/CTAB ratio (0.08?0.25). The materials were characterized by X‐ray powder diffraction, N2 adsorption/desorption isotherm, TEM, TG‐DSC and 29Si MAS NMR. Measurements indicated that the use of mixed surfactants allowed better condensation and higher ordering of the cubic mesostructure; at the same time, some properties of these materials were sensitive to the OP‐10/CTAB ratio. It was also found that the reduced pH of the gel which had been crystallized for a certain time gave a highly reproducible synthesis with a high silica yield (about 95%). Furthermore, the reaction mechanism of the synthesis is discussed in detail. 相似文献