排序方式: 共有113条查询结果,搜索用时 15 毫秒
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Samira Chamyani Hamid R. Shahsavari Sedigheh Abedanzadeh Mohsen Golbon Haghighi Sepideh Shabani Behrouz Notash 《应用有机金属化学》2019,33(1)
Cyclometalated Pt (II) complexes [PtMe(C^N)(L)], in which C^N = deprotonated 2,2′‐bipyridine N‐oxide (Obpy), 1 , deprotonated 2‐phenylpyridine (ppy), 2 , deprotonated benzo [h] quinolone (bzq), 3 , and L = tricyclohexylphosphine (PCy3) were prepared and fully characterized. By treatment of 1–3 with excess MeI, the thermodynamically favored Pt (IV) complexes cis‐[PtMe2I(C^N)(PCy3)] (C^N = Obpy, 1a ; ppy, 2a ; and bzq, 3a ) were obtained as the major products in which the incoming methyl and iodine groups adopted cis positions relative to each other. All the complexes were characterized by means of NMR spectroscopy while the absolute configuration of 1a was further determined by X‐ray crystal structure analysis. The reaction of methyl iodide with 1–3 were kinetically explored using UV–vis spectroscopy. On the basis of the kinetic data together with the time‐resolved NMR investigation, it was established that the oxidative addition reaction occurred through the classical SN2 attack of Pt (II) center on the MeI reagent. Moreover, comparative kinetic studies demonstrated that the electronic and steric nature of either the cyclometalating ligands or the phosphine ligand influence the rate of reaction. Surprisingly, by extending the oxidative addition reaction time, very stable iodine‐bridged Pt (IV)‐Pt (IV) complexes [Pt2Me4(C^N)2(μ‐I)2] (C^N = Obpy, 1b ; ppy, 2b ; and bzq, 3b ) were obtained and isolated. In order to find a reasonable explanation for the observation, a DFT (density functional theory) computational analysis was undertaken and it was found that the results were consistent with the experimental findings. 相似文献
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Pourdasht Sepideh Mousapour Maryam Shirini Farhad Tajik Hassan 《Research on Chemical Intermediates》2022,48(10):4403-4418
Research on Chemical Intermediates - In this work, 1,1-(butane-1,4-diyl)bis(tropinium)chloride is prepared, identified and used for the promotion of the synthesis of polyhydroquinoline and... 相似文献
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Immobilization of copper(I) ions on magnetic nanoparticles was performed using surface modification of Fe3O4 with creatine. Fe3O4@creatine-Cu(I) magnetic catalyst was synthesized and applied in C&bond;X cross-coupling reactions with aryl halides in a deep eutectic as a green solvent. The results indicate the Fe3O4@creatine-Cu(I) magnetic nanoparticles showed excellent activity and high stability. In addition, it was revealed that this catalyst can be recycled five times without significant loss in catalytic activity. 相似文献
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Sepideh Alassi 《BSHM Bulletin: Journal of the British Society for the History of Mathematics》2020,35(2):137-161
Jacob Bernoulli's entries about mechanics in his scientific notebook, the ‘Meditationes’, reveal new facts about the history of the catenary curve. Bernoulli's analyses show that the catenaria, velaria, lintearia and elastica curves together form a family of curves, which I will refer to as the funicularia family. Attending to the history of the whole family of these curves provides remarkable insights into the origin of the catenary problem and the process of its discovery. Studying the ‘Meditationes’ together with Bernoulli's correspondence and publications shows how analysis of one curve led him to the discovery of the others. As a result, this study shows that – although Leonhard Euler is known to be the one who unified the catenary problem and the elastica problem in 1728 – Jacob Bernoulli had in fact proven the same more than thirty years earlier, providing in his notebook a general differential equation for this family of curves. Furthermore, I demonstrate Jacob Bernoulli's priority over his brother Johann in finding the velaria curve. 相似文献
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Kamran Akhbari Sepideh Karami Anukorn Phuruangrat Zahra Saedi 《Journal of the Iranian Chemical Society》2018,15(6):1327-1335
Solid-state conversion of NaI coordination polymer nanostructure, synthesized by sonochemical procedure, to TlI coordination polymer has been observed upon liquid-assisted mechanochemical reaction of [Na2TP] n (1) (H2TP = terephthalic acid), with TlNO3. During this conversion, ion exchange process of Na(I) with Tl(I) was occurred and [Tl2TP] n (2) was synthesized. The X-ray diffraction (XRD) pattern of 2 after mechanochemical reaction of it with NaNO3 indicated that this transformation is irreversible. Compounds 1 and 2 were characterized by IR spectroscopy, X-ray powder diffraction (XRD), elemental analysis, thermogravimetric and differential thermal analyses and scanning electron microscopy. 相似文献
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Magnetite nanoparticles were surface-modified with mercaptoacetic acid (MAA), complexed with Zn(II), and then treated with the dual Schiff base (referred to as imine-based ligand; IBL; obtained by reaction of p-aminobenzoic acid and 2,3-butanedione) to give particles with an architecture of type Fe3O4@MAA@IBL. These are shown to be viable sorbents for magnetic solid phase extraction of organochlorine pesticides (OCPs) from seawater samples. Efficient extraction of the OCPs probably is due to lone pair-π, π-complexation and π-interactions. The sorbent was characterized by transmission electron microscopy, scanning electron microscopy, FT-IR and energy-dispersive X-ray spectroscopy. The effects of the volumes of sample, sorbent dosage and eluent, adsorption and desorption times, and the salinity of the sample on the extraction efficiencies were optimized. The OCPs (heptachlor, aldrin, dieldrin, p,p’-DDE and p,p’-DDT) were quantified by gas chromatography with microelectron capture detection. Under optimal conditions, the limit of detections range was between 1.0 and 1.9 ng L?1. The enrichment factors are between 84.1 and 99.9 %. The sorbent was applied to the rapid extraction of trace quantities of OCPs from seawater samples and gave good relative recoveries (78 to 108 %) and relative standard deviations (<8.3 %). 相似文献
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Mohammad Mahdavi Mehdi Asadi Mahsa Khoshbakht Mina Saeedi Mohammad Bayat Alireza Foroumadi Abbas Shafiee 《Helvetica chimica acta》2016,99(5):378-383
A series of novel quinazolin‐4(3H)‐one derivatives were efficiently synthesized starting from isatoic anhydride. First, reaction of isatoic anhydride and amines in H2O at room temperature afforded 2‐aminobenzamides. Then, CuBr/Et3N promoted reaction of 2‐aminobenzamides and different aryl isothiocyanates in DMF at 80° afforded the title compounds in good yield. 相似文献
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Seyyed Javad Sabounchei Mohsen Ahmadi Fateme Akhlaghi Bagherjeri Farzaneh Hejazi Keyhaneh Sanaie-Noorani Hamid Reza Khavasi Sepideh Samiee 《Comptes Rendus Chimie》2013,16(11):1017-1023
Reaction of Ph3PCHCOC6H4Me (L), with HgX2 and CdCl2·H2O in methanol with equimolar ratios give binuclear complexes of the type [MX(μ-X){CH(PPh3)C(O)C6H4Me}]2 (M = Hg; X = Cl (1), Br (2), I (3), M = Cd; Cl(4)). The bridge-splitting reaction of binuclear complexes [MX(μ-X){CH(PPh3)C(O)C6H4Me}]2 by dimethyl sulfoxide (DMSO) yields the mononuclear complexes [MX2{CH(PPh3)C(O)C6H4Me}(OSMe2)] (M = Hg; X = Cl (5), Br (6), I (7), M = Cd; Cl (8)). The characterization of these complexes was carried out by elemental analysis and FT-IR, 1H, 31P, and 13C NMR spectroscopies. C-coordination of ylide and O-coordination of DMSO are demonstrated by single-crystal X-ray analysis of mononuclear complex of [HgBr2{CH(PPh3)C(O)C6H4Me}(OSMe2)] (6). Complex 6 is monomeric with tetrahedral geometry around the metal ion. 相似文献