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51.
A one-pot multicomponent synthesis of a novel class of cyanophenylamino-acetamides through the conversion of primary amides to the corresponding nitriles, starting from simple and readily available inputs including 2-aminobenzamide, an aldehyde, and an isocyanide in the presence of p-toluenesulfonic acid as a catalyst, in excellent yields at room temperature in ethanol as a green reaction medium is described.  相似文献   
52.
Reaction of phosphorus ylide Ph3PCHC(O)C6H4Cl (Y1) with HgX2 (X = Cl, Br and I) and ylide (p-tolyl)3PCHC(O)CH3 (Y2) with HgI2 in equimolar ratios using methanol as solvent leads to binuclear products. The bridge-splitting reaction of binuclear complex [(Y1) · HgCl2]2 by DMSO yields a mononuclear complex containing DMSO as ligand. O-coordination of DMSO is revealed by single crystal X-ray analysis in mononuclear complex of [(Y1) · HgCl2 · DMSO]. C-coordination of ylides is confirmed by X-ray structure of binuclear complex [(Y2) · HgI2]2. Characterization of the obtained compounds was also performed by elemental analysis, IR, 1H, 31P, and 13C NMR. Theoretical studies on mercury(II) complexes of Y1 show that formation of mononuclear complexes in DMSO solution in which DMSO acts as a ligand, energetically is more favorable than that of binuclear complexes.  相似文献   
53.
The electrocatalytic oxidation of methanol studied at the surface of nickel disc electrode coated with N,N-bis(salicylidene)phenylenediamine (Salophen) legend in 0.10 M NaOH solution using cyclic voltammetry. The results showed that the Ni-salophen layer formed at the surface of electrode behaves as an efficient electrocatalyst for the oxidation of methanol in alkaline medium. The thermal analysis of Ni-salophen complex studied at temperature ranges 0–800°C in argon atmosphere. Also, FTIR was employed to prove the formation of complex on the modified electrode surface. Moreover, the effects of various parameters such as oven temperature, methanol concentration, NaOH concentration and media temperature on electro-oxidation of methanol were investigated. The kinetic parameters such as activation energy and Tafel slope were calculated for methanol oxidation on the modified electrode surface. Published in Elektrokhimiya in Russian, 2009,, 2009, Vol. 45, No. 2, pp. 203–210. The text was submitted by author in English.  相似文献   
54.
A simple, efficient, and new method has been developed for the synthesis of thiiranes from epoxides through a one-pot reaction of epoxides with diethyl phosphite in the presence of ammonium acetate or ammonium hydrogen carbonate/sulfur/ and acidic alumina under solvent-free conditions using microwave irradiation.  相似文献   
55.

The electrochemical behavior of a copper oxide electrode produced by annealing and electrochemical methods was studied in an acetonitrile solvent by means of the cyclic voltammetry method. The presence of different peaks of oxidation and reduction produced by repeating the potential scans, numerous variations in the current, and shifts of peak potentials in consecutive cycles have been justified. Voltammograms proved that various oxidation species can be produced in solid-deposited forms of Cu2Os and CuOs and dissolved forms of Cu(II)sol and Cu(I)sol ions. The experimental results indicated that higher amounts of Cu2Os than CuOs can be produced in the process of copper electrode annealing. Also, the nature of copper species is responsible for different peak currents in the cyclic voltammograms, characterized by UV–Vis and XRD spectrometric methods.

  相似文献   
56.
Hydrogen can be utilized as an energy source; therefore, hydrogen storage has received the most appealing examination interest in recent years. The investigations of hydrogen storage applications center fundamentally around the examination of hydrogen capacity abilities of recently presented compounds. XSrH3 (X = K and Rb) compounds have been examined by density functional theory (DFT) calculations to uncover their different characteristics, as well as hydrogen capacity properties, for the first time. Studied compounds are optimized in the cubic phase, and optimized lattice constants are obtained as 4.77 and 4.99 Å for KSrH3 and RbSrH3, respectively. These hydrides have shown negative values of formation enthalpies as they are stable thermodynamically. XSrH3 might be used in hydrogen storage applications because of high gravimetric hydrogen storage densities, which are 2.33 and 1.71 wt% for KSrH3 and RbSrH3, respectively. Moreover, electronic properties confirm the semiconductor nature of these compounds having indirect band gaps of values 1.41 and 1.23 eV for KSrH3 and RbSrH3, respectively. In addition, mechanical properties from elastic constants such as Young modulus and Pugh's ratio, also have been investigated, and these compounds were found to satisfy born stability conditions. Furthermore, Pugh's ratio and Cauchy pressure show that these hydrides have a brittle nature. Furthermore, thermodynamic properties such as entropy and Debye temperature have been examined using the quasiharmonic Debye model for different temperatures and pressures.  相似文献   
57.
Phosphorus pentoxide supported on silica gel (P2O5/SiO2) has been used as an efficient and reusable catalyst for the one‐pot pseudo four‐component synthesis of 2,4,5‐trisubstituted imidazoles from benzil or benzoin, aldehydes, and ammonium acetate. It was also used for four‐component preparation of 1,2,4,5‐tetrasubstituted imidazoles from benzil or benzoin, aldehydes, primary amine, and ammonium acetate under thermal solvent‐free conditions. The remarkable features of this new procedure are high conversions, cleaner reaction, simple experimental and work‐up procedures and also the catalyst can be easily separated from the reaction mixture and reused several times without any loss of its activity.  相似文献   
58.
Rotational ambiguity is a major problem in the application of soft-modeling analysis to a variety of multivariate mixture resolution problems and particularly important in the analysis of kinetic data. Soft-modeling analyses rely on constraints that restrict the concentration profiles and/or the spectral responses of all components. The main goal of this work is to demonstrate how a hard-modeling constraint on concentration profiles drastically decreases the extent of the rotational ambiguity. Therefore, in the present paper the discussion is focused on systems in which hard-modeling information is available. The results of simulated examples reveal that the utilized hard constraint decreases the rotational ambiguity in estimated concentration profile even components that do not take part in the explicit model. In addition, the rate constant of known reaction is determined in this method.  相似文献   
59.
This procedure works efficiently for high selective mono nitration of phenol and substituted phenol to corresponding nitro compounds in moderate to high yield using poly(4-vinylpyridinium nitrate) and silica sulfuric acid in dichloromethane at room temperature.  相似文献   
60.
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