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91.
1,3,5-Trisubstituted pyrazolines are rapidly and conveniently oxidized to their corresponding pyrazoles by 1,3-dichloro-5,5- dimethylhydantoin(DCH) in solution and solvent-free conditions under microwave irradiation.The presence of silica gel as a supporting agent is shown to be effective in reducing the reaction times and increasing the yields. 相似文献
92.
A simple and efficient method for the synthesis of 9,9‐dimethyl‐9,10‐dihydro‐8H‐benzo‐[α]xanthen‐11(12)‐one derivatives (DDBXs) was developed by the condensation reaction of various substituted aryl al... 相似文献
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94.
In this study, an organic conjugated molecule, 4,4′-[ethane-1,2-diylidenedi(nitrilo)] dibenzenthiol designed and is proposed
as a molecular wire. Structural and electronic responses of this aromatic molecular wire to the static electric field with
intensities −1.6 × 10−2 to +1.6 × 10−2 a.u., are studied using the DFT-B3LYP/6-31G* level of theory. Natural bond orbital atomic charge analysis shows that the
imposition of static external electric field induces polarization—localization of charge on the two ends of molecule, especially
on considered terminal contact sulfur atoms. The frontier molecular orbitals (MOs) energy levels including the highest occupied
MO (HOMO) and the lowest unoccupied MO (LUMO) and the HOMO–LUMO gap (HLG) values are modified by the static electric field
as well. The electric dipole moment and polarizability of the proposed molecular wire under the studied electric field strengths
are considerably increased. The current–voltage characteristic curve is estimated for the proposed molecular wire. 相似文献
95.
In this paper we define the module topological center of the second dual $\mathcal{A}^{**}$ of a Banach algebra $\mathcal{A}$ which is a Banach $\mathfrak{A}$ -module with compatible actions on another Banach algebra $\mathfrak{A}$ . We calculate the module topological center of ? 1(S)**, as an ? 1(E)-module, for an inverse semigroup S with an upward directed set of idempotents E. We also prove that ? 1(S)** is ? 1(E)-module amenable if and only if an appropriate group homomorphic image of S is finite. 相似文献
96.
Rajarama Mohan Jena Snehashish Chakraverty Hadi Rezazadeh Davood Domiri Ganji 《Mathematical Methods in the Applied Sciences》2020,43(7):3903-3913
Fractional Brusselator reaction-diffusion system (BRDS) is used for modeling of specific chemical reaction-diffusion processes. It may be noted that numerous models in nonlinear science are defined by fractional differential equations (FDEs) in which an unknown function appears under the operation of a fractional-order derivative. Even though many researchers have studied the applicability and practicality of this model, the analytical approach of this model is rarely found in the literature. In this investigation, a novel semi-analytical technique called fractional reduced differential transform method (FRDTM) has been applied to solve the present model, which is characterized by the time-fractional derivative (FD). Obtained outcomes are compared with the solution of other existing methods for a particular case. Also, the convergence analysis of this model has been studied here. 相似文献
97.
The one‐pot synthesis of a series of 1,2,4‐triazines from the reactions of semicarbazide or thiosemi‐carbazide with various α,β‐dicarbonyl compounds under reflux conditions in a EtOH‐H2O (9:1) mixture ... 相似文献
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Davood Nori‐Shargh Abolfazl Soofi Nasrin Saroogh Farahani Farzad Deyhimi 《国际化学动力学杂志》2005,37(7):427-433
This work reports the results of a kinetic and mechanistic investigations of the addition reaction of triphenylphosphine to para‐naphtoquinone in 1,2‐dichloromethane as solvent. The order of reaction with respect to the reactants was determined using initial rate method, and the rate constant was obtained on the basis of pseudo‐first‐order method. Variable time method using Uv–Vis spectrophotometry (at 400 nm) was utilized for monitoring this addition reaction, for which the following Arrhenius equation was obtained: The resulting activation parameters Ea, ΔH#, ΔG#, and ΔS# at 300 K were 13.63, 14.42, 18.75 kcal mol?1, and ?14.54 cal mol?1K?1, respectively. The results suggest that the reaction is first order with respect to both triphenylphosphine and para‐naphthoquinone. © 2005 Wiley Periodicals, Inc. Int J Chem Kinet 37: 427–433, 2005 相似文献
100.
An efficient and one-pot electrochemical method for the synthesis of methylene blue based on the Michael-type reaction of electrochemically generated quinone-diimine derived from oxidation of N,N-dimethyl-p-phenylenediamine in the presence of sodium sulfide as nucleophile in aqueous solution via EC-ECECC mechanism is reported. 相似文献