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Samaneh Mahmoudi‐GomYek Davood Azarifar Masoumeh Ghaemi Hassan Keypour Masoumeh Mahmoudabadi 《应用有机金属化学》2019,33(6)
A novel Cu (II) Schiff‐base complex immobilized on core‐shell magnetic Fe3O4 nanoparticles (Fe3O4@SPNC) was successfully designed and synthesized. The structural features of these nanoparticles were studied and confirmed by using various techniques including FT‐IR spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy‐dispersive X‐ray spectroscopy (EDS), vibrating sample magnetometer (VSM), X‐Ray diffraction (XRD), wavelength dispersive X‐ray spectroscopy (WDX), and inductively coupled plasma (ICP). These newly synthesized nanoparticles have been used as efficient heterogeneous catalytic system for one‐pot multicomponent synthesis of new pyrano[2,3‐b]pyridine‐3‐carboxamide derivatives. Notably, the catalyst could be easily separated from the reaction mixture by using an external magnet and reused for several successive reaction runs with no significant loss of activity or copper leaching. The present protocol benefits from a hitherto unreported MNPs‐immobilized Cu (II) Schiff‐base complex as an efficient nanocatalyst for the synthesis of newly reported derivatives of pyrano[2,3‐b]pyridine‐3‐carboxamide from one‐pot multicomponent reactions. 相似文献
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Mohammad Yousefi Elham Noori Davood Ghanbari Masoud Salavati-Niasari Tahereh Gholami 《Journal of Cluster Science》2014,25(2):397-408
In this work, poly vinyl alcohol–ZnO nanocomposites were synthesized via two different in situ and ex-situ methods. In ex-situ, at first zinc oxide nanostructures were synthesized by one-step precipitation reaction between zinc acetate and sodium hydroxide. The effect of different surfactants such as poly vinyl pyrrolidone, poly vinyl alcohol and poly ethylene glycol on the morphology of ZnO nanostructures was investigated. Nanostructures were characterized by X-ray diffraction, scanning electron microscopy. The influence of ZnO nanostructures on the flame retardancy of the poly vinyl alcohol matrix was studied using underwriter laboratories UL-94 analysis. 相似文献
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In this research, the main emphasis has been focused on the preparation of a novel Fe3O4-supported propane-1-sulfonic acid-grafted graphene oxide quantum dots (Fe3O4@GOQD-O-(propane-1-sulfonic acid)) that it was readily synthesized via a five-step procedure as a hitherto unreported magnetic nanocatalyst. This newly prepared Fe3O4@GOQD-O-(propane-1-sulfonic acid) nanocomposite was structurally well-established by different analytical techniques including Fourier transform infrared (FT-IR), X-ray diffraction (XRD), energy-dispersive X-ray (EDX), thermal gravimetric analysis (TGA), field emission gun-scanning electron microscope (FESEM), high-resolution transmission electron microscopy (HRTEM) and vibrating sample magnetometer (VSM) analyses. The high catalytic performance of this nanocomposite was exhibited in one-pot synthesis of dihydropyrano[2,3-c]pyrazole and 4H-chromene derivatives under mild conditions. Low reaction times, excellent yields of the products, benignity of the catalyst, easy reaction work-up and magnetic recyclability of the catalyst are the main advantages of the present protocol. Also, our research indicated that the Fe3O4@GOQD-O-(propane-1-sulfonic acid) could be reused up to five times without considerable loss of catalytic activity. 相似文献
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Electrochemical oxidation of 2,3‐dihydroxypyridine in aqueous phosphate buffer solution at a glassy carbon electrode has been studied using cyclic voltammetry and controlled potential coulometry. The results indicate that oxidation of 2,3‐dihydroxypyridine on glassy carbon electrode shows an irreversible feature in aqueous solution. This data indicates that the electrochemically generated pyridindione is unstable and via an oxidative conversion pathway converts to a novel highly oxygenated heterocyclic compound. By means of the obtained electrochemical data, an efficient, one‐pot method for the synthesis of this heterocyclic compound based on the oxidative cyclization of 2,3‐dihydroxypyridine under green conditions, and in a good yield and purity is described. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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Mohammad Mehdi Khodaei Davood Kordestani 《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):2403-2405
Abstract Direct conversion of acylals to the corresponding bisulfites can be easily performed in the presence of bismuth (III) nitrate pentahydrate in ethanol at room temperature in good yields. 相似文献
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Saleh Ashrafi Okhtay Jahanbakhsh Davood Alizadeh Behrooz Salehpour 《Central European Journal of Physics》2013,11(5):560-567
Compton scattering tomography is widely used in numerous applications such as biomedical imaging, nondestructive industrial testing and environmental survey, etc. This paper proposes the use of the genetic algorithm (GA), which utilizes bio-inspired mathematical models, to construct an image of the insides of a test object via the scattered photons, from a voxel within the object. A NaI(Tl) scintillation detector and a 185 MBq 137Cs gamma ray source were used in the experimental measurements. The obtained results show that the proposed GA based method performs well in constructing images of objects. 相似文献
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Davood Nori-Shargh Daryoush Tahmassebi Mahboobeh Poukalhor Mostafa Mohammadpour Amini Saeed Jameh-Bozorghi Farzad Deyhimi 《Phosphorus, sulfur, and silicon and the related elements》2013,188(10):2419-2434
Ab initio molecular orbital and density functional theory were used to investigate energetic and structural properties of the various conformations of hexa-tertbutylbenzene (1), hexakis(trimethylsilyl)benzene (2), hexakis (trimethylgermyl)benzene (3), and hexakis(trimethylstannyl)benzene (4). HF/3-21G//HF/3-21G and B3LYP/3-21G//HF/3-21G results revealed that the Twist-Boat (TB) conformer of compound 1 is more stable than the 1-Chair (C), 1-Boat (B), and 1-Planar (P) conformers. B3LYP/3-21G//HF/3-21G results show that the 1- TB conformer is more stable than 1- C, 1- B, and 1- P conformers of about 1.13, 4.34, and 99.94 kcal mol?1 , respectively. Contrary to the stability order of compound 1 conformers, the C conformer of compounds 2–4 is more stable than TB, B, and P conformations, as calculated by B3LYP/3-21G//HF/3-21G and HF/3-21G//HF/3-21G levels of theory. The energy gap between the C and P conformers in compounds 1–4 is decreased in the following order: ΔE(4: C, P) < ΔE (3: C, P) < ΔE(2: C, P) < ΔE (1: C, P). This fact can be explained in terms of the increase of C aromatic -M (M═C, Si, Ge, and Sn) bond lengths and the decrease of steric (van der Waals) repulsions in the previously discussed compounds. For compounds 1–3, the calculations were also performed at the B3LYP/ 6-31G*//HF/3-21G level of theory. However, the comparison showed that the results at B3LYP/3-21G//HF/3-21G methods correlated well with those obtained at the B3LYP/6-31G*// HF/6-31G method. Further, NBO analysis revealed that in compounds 1–4, the resonance energy associated with the σM-C1 to σ*C2-C3 delocalization is 5.20, 9.68, 11.15, and 12.27 kcal mol?1, respectively. These resonance energy values could explain the easiness of the ring flipping processes of C, B, and TB conformers of compounds 4 to 1. Also, the NBO results showed that by an increase of the σM-C1 → σ *C2-C3 resonance energies in compounds 1–4, the σM-C1 bonding orbital occupancies decrease. This fact could fairly explain the increase of the Caryl-M bond length from compound 1 to 4. The NBO results are also in good agreement with the calculated energy barriers for the ring flipping of the chair conformations in compounds 1–4, as calculated by B3LYP and HF methods. 相似文献