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61.
Idriss Bakas Gorkem Yilmaz Zouhair Ait‐Touchente Aazdine Lamouri Philippe Lang Nicolas Battaglini Benjamin Carbonnier Mohamed M. Chehimi Yusuf Yagci 《Journal of polymer science. Part A, Polymer chemistry》2016,54(21):3506-3515
The surface chemistry of aryl diazonium salts has progressed at a remarkable pace in the last two decades, and opened many avenues in materials science. These compounds are excellent coupling agents for polymers to surfaces via several surface‐confined polymerization methods. For the first time, we demonstrate that diazonium salts are efficient for surface initiating radical photopolymerization in the visible light of methyl methacrylate (MMA) and 2‐hydroxyethyl methacrylate (HEMA) taken as model monomers. To do so, 4‐(dimethylamino)benzenediazonium salt was electroreduced on gold plates or flexible ITO sheets to provide 4‐(dimethylamino)phenyl (DMA) hydrogen donor layers; while excited state camphorquinone acted as the free hydrogen abstractor. In the same way, we co‐polymerized HEMA and MMA with ethylene glycol dimethacrylate in order to obtain crosslinked polymer grafts. We demonstrate by XPS that gold was efficiently screened by the polymer layers and that the wettability of the surfaces accounts for the hydrophilic or hydrophobic characters of the tethered polymers. Homo‐ and crosslinked PMMA grafts were found to resist removal by the paint stripper methyl ethyl ketone. The grafted DMA/camphorquinone system operating in the visible light holds great promises in terms of adhesion of in situ designed continuous or patterned polymer coatings on various substrates. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 3506–3515 相似文献
62.
Miller G. Makramalla Monica T. Diab Cody N. Sherren Arthur D. Hendsbee Jason D. Masuda Katherine N. Robertson 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):1537-1554
Abstract The reactivity of ketenylidenetriphenylphosphorane (1) with the protic reagents 2,4,6-trimethylphenol (7), 2,6-di-tert-butyl-4-methylphenol (8), and diphenylamine (9) has been explored. Three novel carbonyl-stabilized ylides have been synthesized and characterized. Crystal structures were obtained for Ph3PCHC(O)O(C6H2Me3) (11), Ph3PCHC(O)O(C6H2t-Bu2Me) (12), and Ph3PCHC(O)NPh2 (13), respectively. These products were then methylated in an attempt to develop a new route to low-valent carbon compounds. Crystals of [Ph3PCH(CH3)C(O)O(C6H2Me3)]I (14) were isolated and characterized but this route did not prove to be synthetically useful, at least toward the goal of preparing low-valent carbon-centered materials. Finally, 1 was also reacted with the bulky tin reagent, bis[bis(trimethylsilyl)amido]tin(II), in the presence of 2,4,6-trimethylphenol. A complex mixture of products was obtained, from which crystals of an unusual chelated tin compound (15) were isolated and characterized using X-ray crystallography. 相似文献
63.
John B. Bauer Fatima Diab Ccilia Maichle-Mssmer Hartmut Schubert Holger F. Bettinger 《Molecules (Basel, Switzerland)》2021,26(10)
The Diels–Alder cycloaddition between bisdienes and bisdienophile incorporating the 7-oxa-bicyclo[2.2.1]heptane unit are well known to show high diastereoselectivity that can be exploited for the synthesis of molecular belts. The related bisdiene 5,6,7,8-tetramethylidene-2-bicyclo[2.2.2]octene is a valuable building block for the synthesis of photoprecursors for acenes, but it has not been employed for the synthesis of molecular belts. The present work investigates by computational means the Diels–Alder reaction between these bisdiene building blocks with syn-1,4,5,8-tetrahydro-1,4:5,8-diepoxyanthracene, which shows that the diastereoselectivity of the Diels–Alder reaction of the etheno-bridged bisdiene is lower than that of the epoxy-bridged bisdiene. The reaction of the etheno-bridged bisdiene and syn-1,4,5,8-tetrahydro-1,4:5,8-diepoxyanthracene in 2:1 ratio yields two diastereomers that differ in the orientation of the oxa and etheno bridges based on NMR and X-ray crystallography. The all-syn diastereomer can be transformed into a molecular belt by inter- and intramolecular Diels–Alder reactions with a bifunctional building block. The molecular belt could function as a synthetic intermediate en route to a [11]cyclacene photoprecursor. 相似文献
64.
Bouzina Abdeslem Berredjem Malika Belhani Billel Bouacida Sofiane Marminon Christelle Le Borgne Marc Bouaziz Zouhair Aissaoui Mohamed 《Research on Chemical Intermediates》2021,47(4):1359-1376
Research on Chemical Intermediates - We demonstrate here a rapid and comfortable synthetic sequence to benzothiadiazinone dioxide (six-membered cyclic sulfamide) derivatives, analogues of... 相似文献
65.
El-Sonbati AZ Diab MA El-Bindary AA Nozha SG 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,83(1):490-498
The synthetic methods of novel Cu(II) and adduct complexes, with selective azodyes containing nitrogen and oxygen donor ligands have been developed, characterized and presented. The prepared complexes fall into the stoichiometric formulae of [Cu(L(n))(2)](A) and [Cu(L(n))(2)(Py)(2)](B), where two types of complexes were expected and described. In type [(A) (1:2)] the chelate rings are six-membered/four coordinate, whereas in type [(B) (1:2:2)] they are six-membered/six coordinate. The important bands in the IR spectra and main (1)H NMR signals are tentatively assigned and discussed in relation to the predicted assembly of the molecular structure. The IR data of the azodye ligands suggested the existing of a bidentate binding involving azodye nitrogen and C-O oxygen atom of enolic group. They also showed the presence of Py coordinating with the metal ion. The coordination geometries and electronic structures are determined from the framework of the proposed modeling of the formed novel complexes. The complexes (1-5) exist in trans-isomeric [N,O] solid form, while adduct complexes (6-10) exist in trans isomeric (Py) form. The square planar/octahedral coordination geometry of Cu(II)/adduct is made up of an N-atom of azodye, the deprotonated enolic O-atom and two Py. The azo group was involved in chelation for all the prepared complexes. ESR spectra show the simultaneous presence of a planar trans and a nearly planar cis isomers in the 1:2 ratio for all N,O complexes [Cu(L(n))(2)]. The ligands in the dimmer are stacked over one another. In the solid state of azo-rhodanine, the dimmers have inter- and intramolecular hydrogen bonds. Interactions between the ligands and Cu(II) are also discussed. 相似文献
66.
Diab MA El-Sonbati AZ Bader DM 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,79(5):1057-1062
N-(biphenylmethylidenyl) chitosan polymer was prepared, characterized and thermal stability was compared with chitosan. Thermal degradation products of the modified polymer were identified by GC-MS technique. It seems that the mechanism of degradation of the prepared polymer is characterized by formation of low molecular weight radicals, followed by random scission mechanism along the backbond chain. 相似文献
67.
68.
Thermoluminscence (TL) properties of quaternary tellurite glass in the form 80(TeO2)–5(TiO2)–(15−x)(WO3)–(x)AnOm where AnOm=Nb2O5, Nd2O3, Er2O3 and x mol% have been measured. TL main dosimetry peak for each produced glass sample were investigated for 60Co gamma rays. Dosimetric properties of the quaternary tellurite glasses have been measured as a function of different compositions of the glass system in different rare earth oxides concentration by using thermoluminescence (TL) detection technique. 相似文献
69.
An approach to evaluate the efficiency of γ-ray detectors to determine the radioactivity in environmental samples 下载免费PDF全文
Mohamed. S. Badawi Ahmed. M. El-Khatib Samah. M. Diab Sherif. S. Nafee Ekram. A. El-Mallah 《中国物理C(英文版)》2014,38(6):066203-066203
This work provides an approach to determine the efficiency of γ-ray detectors with a good accuracy in order to determine the concentrations of either naturally occurring or artificially prepared radionuclides. This approach is based on the efficiency transfer formula (ET), the effective solid angles, the self- absorptions of the source matrix, the attenuation by the source container and the detector housing materials on the detector efficiency. The experimental calibration process was done using radioactive (Cylindrical & Marinelli) sources, in different dimensions, that contain aqueous 152Eu radionuclide. The comparison point to a fine agreement between the experimental measured and calculated efficiencies for the (NaI & HPGe) detectors using volumetric radioactive sources. 相似文献
70.
An investigation of classical fields with fractional derivatives is presented using the fractional Hamiltonian formulation. The fractional Hamilton’s equations are obtained for two classical field examples. The formulation presented and the resulting equations are very similar to those appearing in classical field theory. 相似文献