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51.
Arash Ghorbani-Choghamarani Ali Naghipour Heshmatollah Babaee Hayedeh Heidarnezhad Behrouz Notash 《Journal of the Iranian Chemical Society》2018,15(9):2123-2134
In this study, palladium (II) chloride reacted with the phosphonium salt [PhCH2COOCH2P(Ph)3]Br to give [PhCH2COOCH2P(Ph)3]2[Pd2Br6] (1). The characterization of synthesized compound was performed by elemental analysis, FT-IR, 1H, 31P, 13C NMR and also X-ray crystallography. It was found that this compound works as an efficient catalyst for the amination of aryl halides to afford primary amines, the results of which were satisfactory. Furthermore, it was found that the catalyst showed a high activity for Suzuki carbon–carbon cross-coupling of aryl halides and phenylboronic acid. Interestingly, the catalyst can be recovered from the reaction mixture and recycled four consecutive runs without any significant loss in activity. 相似文献
52.
The one-pot four-component synthesis of highly functionalized fused hydroxyl dihydropyrroles and dihydropyrazines from readily available diamines, 1,1-bis (methylsulfanyl)-2-nitroethene, phenylglyoxal monohydrates, and C-H acids have been developed. This strategy provides an efficient, catalyst-free approach for easy access to various new hydroxyl-dihydropyrrole and dihydropyrazine rings in good to high yields. The products were confirmed by 1H and 13C NMR, IR, mass, and X-ray crystal structure analyses. 相似文献
53.
Firouzeh Nemati Ali Ghorbani Gharjeh Ghiyaei Behrouz Notash Mojtaba Hajiloo Shayegan Vahid Amani 《Tetrahedron letters》2014
An efficient route for the synthesis of gem-bis(dithiocarbamate) derivatives is developed using dithiocarbamic acid salts generated from primary aliphatic amines and CS2. The method offers high yields, employs mild reaction conditions, and demonstrates excellent functional group compatibility. The structures of the products were confirmed spectroscopically and by X-ray analysis. 相似文献
54.
55.
In this paper we consider an unconstrained and a constrained minimization problem related to the boundary value problem . In the unconstrained problem we minimize an energy functional relative to a rearrangement class, and prove existence of a unique solution. We also consider the case when D is a planar disk and show that the minimizer is radial and increasing. In the constrained problem we minimize the energy functional relative to the intersection of a rearrangement class with an affine subspace of codimension one in an appropriate function space. We briefly discuss our motivation for studying the constrained minimization problem.
相似文献
$$ - {\Delta _p}u = f{\text{ in }}D,{\text{ }}u = 0{\text{ on }}\partial D$$
56.
A novel calix[4]arene derivative with two ferrocenyl Schiff-base groups at the upper rim 3 has been synthesized from 5,17-diformyl-25,27-dipropoxy-26,28-dihydroxy calix[4]arene and 4-ferrocenylaniline via condensation reaction. Reduction of 3 with sodium borohydride led to calix[4]arene derivative 4 with two amino ferrocenyl groups at the upper rim. The ferrocenyl Schiff-base calix[4]arene and its corresponding reduced amine have been purified and characterized by elemental analysis,1H NMR, FTIR, Mass and UV-vis spectral data. Electrochemical properties of compounds 3 and 4 have been investigated. Cyclic voltammograms of 3 and 4 show reversible redox couples of ferrocene/ferrocinium at E1/2=0.401 V and 0.346 V, respectively. Electrochemical studies show these redox active compounds electrochemically recognize trivalent lanthanides La3+ and Ce3+ and divalent Pb2+ and Cu2+cations. With ferrocenyl Schiff-base calix[4]arene 3 an anodic shift as large as 130 mV is observed on addition of one equivalent of Ce3+ ion. Also extraction properties of compound 4 towards some metal cations have been described. It has been observed that compound 4 has a good selectivity for metal cations Fe3+, Cu2+, Pb2+ and Cd2+ against Ni2+ and Co2+. 相似文献
57.
This study presents for the first time development of a highly selective and sensitive thulium(III) micro‐sensor. Theoretical calculations were conducted on a S‐N Schiff base [thiophene‐2‐carbaldehyde‐(7‐methyl‐1,3‐benzothiazol‐2‐yl) hydrazone] (TCMH) in order to obtain a clue about the tendency of TCMH to Tm(III) and some other metal ions. Then, TCMH was used as a membrane‐active component to prepare a Tm(III)‐selective polymeric membrane microelectrode. In line with the resulting data, the electrode exhibits a Nernstian response toward Tm(III) ions for a very wide concentration range (1.0×10?11–4.0×10?6 M) with a detection limit of 1.0×10?11 (ca. 1.5 ppt) and a very fast response time in the whole concentration range (<5 s). In addition, the results showed that the certain microelectrode could be applied in the pH range of 4.0–11.0 with a usage of more than one month without any considerable potential divergence. 相似文献
58.
Behrouz Tabarrok Roy L. Sakaguchi 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1969,20(3):423-428
Zusammenfassung Das Problem der schwingenden Platte wird mit Hilfe des Hamiltonischen Prinzips und des komplementären Prinzips formuliert. Es wird gezeigt, dass das komplementäre Prinzip auf drei Bewegungsgleichungen an Stelle einer einzigen führt. Die Randbedingungen werden bei der rechteckigen Platte für beide Formulierungen des Problems angegeben. Für die Eigenfrequenzen der freien Rechteckplatte ergibt sich mit dem komplementären Prinzip eine deutliche Verbesserung gegenüber dem Hamiltonischen Prinzip bei Behandlung mit dem Ritzschen Verfahren. 相似文献
59.
The pertinent equations of naturally curved and pretwisted rods, in the form of compatibility, equilibrium and constitutive relations are obtained under the assumptins of infinitesimal deformations and material isotropy. Then by forming the expressions for various energy terms, the equations of motion of the rod are obtained via Hamilton's principle and the complementary energy principle. On comparing these two forms of equations of motion, and the associated boundary conditions certain dualities are exposed. Finally the equations of some special rods, including the plane arch and the straight pretwisted rod, are examined. 相似文献
60.
Alan R. Katritzky Boris V. Rogovoy Christophe Chassaing Vladimir Vvedensky Behrouz Forood Brenton Flatt Hisao Nakai 《Journal of heterocyclic chemistry》2000,37(6):1655-1658
The condensation of α,β‐unsaturated ketones with substituted o‐aminothiophenols, obtained by reductive cleavage of the corresponding disulfides in the presence of triphenylphosphine, is an effective method for the synthesis of 2,4‐diaryl‐2,3‐dihydro‐1,5‐benzothiazepines under neutral conditions. 相似文献