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11.
Mostafa Mohsen M. El-Shazly Rafaat M. Rakha Tawfik H. Abdel-Rahman Mohamed H. 《Transition Metal Chemistry》2002,27(3):337-340
Tribochemical reactions of KBr, KI and CaI2 with [Cu(L)Cl2(EtOH)3/2(H2O)]1/2H2O (L = formylhydrazine) give novel CuI and CuII complexes, which have been characterized by elemental analyses, spectral (i.r., u.v.–vis., 1H-n.m.r.) and magnetic measurements. The i.r. spectra indicate that (L) behaves in a monodentate manner, coordinating via the azomethine nitrogen (C-N) group in the CuII complexes, but behaving as a bidentate ligand, via the carbonyl oxygen and NH2 groups in the CuI complexes. KI and CaI2 react with [Cu(L)Cl2(EtOH)3/2(H2O)]-1/2H2O in the solid state, accompanied by a colour change, substitution of the chloride by iodide ions, and reduction of CuII to CuI to give complexes with formulae [Cu(L)I(EtOH)1/2] and [Cu1.7(L)I1.7(EtOH)1/2]. On the other hand, the tribochemical reaction of KBr with [Cu(L)Cl2(EtOH)3/2(H2O)]1/2H2O is accompanied by a colour change; substitution of the chloride by bromide ions, but without reduction of CuII and yields a complex of formula [Cu(L)2Br2(EtOH)(H2O)]1/2EtOH. The spectral and magnetic results suggest a distorted octahedral geometry for the CuII complexes while a tetrahedral geometry around the CuI ion. The non-stoichiometric structure of [Cu1.7(L)I1.7(EtOH)1/2] is discussed. 相似文献
12.
A synthesis of 5,11b-dihydro-1H-dibenzo[d,f][1,3]diazepin-1-ones was found in the reaction of nitro-substituted N1,N2-diarylamidines with 3,4,5,6-tetrachloro-1,2-benzoquinone. In contrast, 6,7,8,9-tetrachlorodibenzodioxins were obtained from reaction of N1,N2-diphenylpropionamidine and N1,N2-di-(4-tert-butylphenyl)acetamidine with 3,4,5,6-tetrachloro-1,2-benzoquinone. 相似文献
13.
Hooman Moradpour Mohsen Javaherian Ebrahim Namvar Amir Hadi Ziaie 《Entropy (Basel, Switzerland)》2022,24(6)
Relying on the quantum tunnelling concept and Maxwell–Boltzmann–Gibbs statistics, Gamow shows that the star-burning process happens at temperatures comparable to a critical value, called the Gamow temperature () and less than the prediction of the classical framework. In order to highlight the role of the equipartition theorem in the Gamow argument, a thermal length scale is defined, and then the effects of non-extensivity on the Gamow temperature have been investigated by focusing on the Tsallis and Kaniadakis statistics. The results attest that while the Gamow temperature decreases in the framework of Kaniadakis statistics, it can be bigger or smaller than when Tsallis statistics are employed. 相似文献
14.
In this paper we derive a Gaussian flux integral for a metric in the weak field limit. We shall prove that the energy integral for an approximately linear metric due to a scalar field, will possess a same form for the Newtonian mass. 相似文献
15.
Fathia Rajah Mohsen Graia Tahar Mhiri 《Phosphorus, sulfur, and silicon and the related elements》2013,188(9):1244-1253
Abstract Sodium copper (II) arsenate Na7Cu4(AsO4)5 has been grown by conventional high-temperature, solid-state methods in molten-salt media. It was characterized by single crystal X-ray diffraction (XRD), thermal analysis (DTA–TGA), scanning electron microscopy (SEM), semiquantitative energy dispersive spectroscopy analysis (EDS), and vibrational spectroscopy. Na7Cu4(AsO4)5 exhibits a three-dimensional framework built up of CuO5, CuO4, and AsO4 polyhedra, with intersecting channels in which the Na+ cations are located. The three-dimensional cohesion of the framework results from Cu–O–As bridges. CuO5 and CuO4 polyhedra are elongated due to the Jahn–Teller effect, whereas AsO4 tetrahedra are almost regular. This new structural model is validated by the charge distribution (CD) analysis. The infrared and Raman spectra confirmed the presence of AsO4 tetrahedra. [Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfer, and Silicon and the Related Elements for the following free supplemental files: Additional tables and figures.] 相似文献
16.
Mohsen Abbaspour 《Chemical physics》2012,392(1):107-113
The Fowler’s expression for calculation of the reduced surface tension and surface energy has been used with Lennard-Jones (LJ) and two-body Hartree-Fock dispersion (HFD)-like potentials for neon and argon, respectively. The required radial distribution functions (RDFs) have been used from two recently determined expressions in the literature and a new equation proposed in this work. Quantum corrections for neon system have been considered using the Feynman-Hibbs (FH) and Wigner-Kirkwood (WK) approaches. To take many-body forces into account for argon system, the simple three-body potentials of Wang and Sadus (2006) [33] and Hauschild and Prausnitz (1993) [30] used with the HFD-like potential without requiring an expensive three-body calculation. The results show that the quantum and three-body effects improve the prediction of the surface tension of liquid neon and argon using the Fowler’s expression. 相似文献
17.
Taxane group of diterpenoids 2 and 3 which possess cinnamoyl moiety at C-5 position underwent selective cleavage to C-5 hydroxy compounds 4 and 5 on treatment with hydroxylamine. The resulting compounds were characterised based on their spectral data. 相似文献
18.
Zeinab Noroozi Tisseh Minoo Dabiri Mohsen Nobahar Hamid Reza Khavasi Ayoob Bazgir 《Tetrahedron》2012,68(6):1769-1773
An approach for the synthesis of new 5-substituted-tetrazoles via multi-component domino Knoevenagel condensation/1,3 dipolar cycloaddition reaction of carbonyl compounds, malononitrile and sodium azide in water without assistance of any catalyst has been reported. This general protocol provides a wide variety of 5-substituted 1H-tetrazoles in good yields under mild reaction conditions. 相似文献
19.
Issa Yavari Mansoureh Aghazadeh Mohsen Tafazzoli 《Phosphorus, sulfur, and silicon and the related elements》2013,188(5):1101-1107
Ethyl 2-arylamino-2-oxo-acetates undergo a complex reaction with dimethyl acetylenedicarboxylate in the presence of triphenylphosphine to produce dimethyl 1-aryl-4-ethoxy-5-oxo-4,5-dihydro-1 H -pyrrole-2,3-dicarboxylates in good yields. Dynamic NMR study of dimethyl 1-(2-methylphenyl)-4-ethoxy-5-oxo-4,5-dihydro-1 H -pyrrole-2,3-dicarboxylate shows a fairly high energy barrier ( j G p = 53.2 kJmol m 1 ) for rotation around the N-aryl single bond, which leads to an observable atropisomerism. 相似文献
20.
Alireza Hasaninejad Khodabakhsh Niknam Abdolkarim Zare Ehsan Farsimadan Mohsen Shekouhy 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):147-155
Silphox [POCl3-n(SiO2)n] efficiently catalyzes the condensation of benzene-1,2-diamine with mono and dicarboxylic acids under microwave irradiation to afford benzimidazole derivatives in high yields and short reaction times. 相似文献