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11.
Bimetallic Gold(I) Complexes with Ethynyl‐Helicene and Bis‐Phosphole Ligands: Understanding the Role of Aurophilic Interactions in their Chiroptical Properties
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Dr. Mehdi El Sayed Moussa Dr. Hui Chen Zuoyong Wang Dr. Monika Srebro‐Hooper Dr. Nicolas Vanthuyne Dr. Soizic Chevance Prof. Christian Roussel Prof. J. A. Gareth Williams Prof. Jochen Autschbach Prof. Régis Réau Prof. Zheng Duan Dr. Christophe Lescop Dr. Jeanne Crassous 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(17):6075-6086
Monometallic gold(I)‐alkynyl‐helicene complexes ( 1 a , b ) and bimetallic gold(I)‐alkynyl‐helicene architectures featuring the presence ( 2 a , b ) or absence ( 3 a , b ) of aurophilic intramolecular interactions were prepared by using different types of phosphole ligands (mono‐phosphole L1 or bis‐phospholes L2 , 3 ). The influence of the AuI d10 metal center(s) on the electronic, photophysical, and chiroptical properties of these unprecedented phosphole‐gold(I)‐alkynyl‐helicene complexes was examined. Experimental and theoretical results highlight the importance of ligand‐to‐ligand‐type charge transfers and the strong effect of the presence or absence of AuI–AuI interactions in 2 a , b . 相似文献
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Khalid Bouras Abdelmonaim El Kaddouri Jawad H’michane Mohammed Moussa 《Rendiconti del Circolo Matematico di Palermo》2012,61(3):355-360
We characterize Banach lattices on which each positive operators is b-weakly compact and we derive some characterizations of KB-spaces. 相似文献
15.
The reaction of 1,1,1-trichloro-3,3,3-trifluoroacetone with 1[ddot] and 2[ddot] alcohols form the corresponding hemiketals which spontaneously eliminate water in presence of a catalytic amount of p-toluenesulfonic acid to produce the olefins in high yield. 相似文献
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Hassan Talaat Ali H. Moussa M. Shalaby El-Wallid S. Sedik M. Tag El-Din Kamal 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2013,87(3):454-460
We apply the time-dependent theory to the collinear exchange reaction F + CH4 → FCH3 + H. We have performed detailed calculations on two-dimensional potential surfaces representing the ground electronic potentials of the collinear F + CH4 → FCH3 + H reaction, at incident energies. Transmission coefficients range from zero to unity, depending upon the incident energy. Normal modes of vibrations are displayed along the reaction path. 相似文献
17.
Ahmed Hanan A. Moussa Bahia A. El-Bagary Ramzia I. Darwish Mahmoud N. 《平面色谱法杂志一现代薄层色谱法》2013,26(1):56-61
JPC – Journal of Planar Chromatography – Modern TLC - Three selective, precise, and accurate methods were developed and validated for the simultaneous determination of ofloxacin and... 相似文献
18.
Fractal analysis of hydroxyapatite from nitrogen isotherms 总被引:10,自引:0,他引:10
Samples of calcium hydroxyapatite, CaHap, were prepared via a wet method and subjected to thermal treatment in air in the temperature range 100-900 degrees C. Nitrogen adsorption-desorption isotherms were obtained on different samples, and their data points were used to analyze the fractal properties of the obtained solids. Both FHH and Neimark's equations were used for such purpose, and the agreement or disagreements between obtained results on using both equations are discussed. Considering the appropriate values of the obtained surface fractal dimensions D, it was concluded that an appreciable defractalization of the prepared hydroxyapatite is only noted upon calcinations at 900 degrees C. Below this temperature the loss in surface area and pore volume result from simultaneous bulk and surface mass transport, which conserve the initial surface roughness and average pore radius. Calcination at 900 degrees C caused sintering to proceed via bulk mass transport, with a consequent pore widening and a decrease in surface roughness. 相似文献
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Saleh A. Ahmed Ziad Moussa Shaya Y. Al‐Raqa Saleh N. Alamry 《Journal of Physical Organic Chemistry》2009,22(6):593-606
Multi‐addressable photophysical properties of new synthesized photochromic materials based on photochromic dihydroindolizine system (DHI) covalently linked to N‐acyl‐11 aminoundecanoic acid (AUDA) or to its sodium salt or to its ester, through an amidic or urethane linkage have been studied. The DHI skeleton in these compounds is substituted in both the fluorene part (region A) or in the heterocyclic base (region B) with the gelling moieties. These molecules have been designed to respond to their environment. Interestingly, they are shown to act as efficient gelators for polar organic fluids, water and obviously they exhibit a thermosensitive answer as low molecular mass organogelators. In these fluids, the aggregative properties are totally suppressed upon conversion to neutral carboxylic species. The gels of these carboxylate sodium salts are shown to be markedly affected by light irradiation. Supramolecular gelating assemblies can be disrupted by the photoinduced ring opening of the DHI subunit, so that the macroscopic flowing property is recovered. Upon a further thermal treatment, the system is reversibly converted back to the supramolecular network. Controlled gelation could be achieved using temperature, light, or acidity as external stimuli. These new synthesized photochromic gels with their multi‐addressable properties will find their applications as super photoresponsive materials. Developing and tuning of the photophysical properties of the synthesized compounds by the amide and urethane substituents in the 4‐position of the fluorene and pyridazine regions have been achieved. The absorption maxima (λmax) and the half‐lives (t1/2) of the colored betaines were detected in all cases using UV/VIS spectrophotometric measurements. Irradiation of DHI 12‐20 in CH2Cl2 or in acetonitrile solutions at ambient temperature with polychromatic light leads to the formation of red to red‐violet colored betaines 12 ′ ‐20 ′. The kinetics of the bleaching process of betaines 12 ′ ‐20 ′ to DHIs 12‐20 were found to take place in the second range (96‐218 s) and fit well the first order thermal back reaction. Some of these DHIs showed a photostability higher than that of the standard one. These interesting photophysical properties will help this family of compounds to find useful applications. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
20.
JPC – Journal of Planar Chromatography – Modern TLC - A simple, rapid, and selective densitometric thin-layer chromatographic (TLC) method has been established and validated for... 相似文献