排序方式: 共有16条查询结果,搜索用时 31 毫秒
1.
Sherin A. Saraireh Mohammednoor Altarawneh Mouad A. Tarawneh 《Surface and interface analysis : SIA》2020,52(4):156-166
These contributions explore interaction modes between the methanethoil (CH3SH) molecule and the Fe(100) surface via implementing accurate density functional theory (DFT) calculations with the inclusion of van der Waals corrections. We consider three adsorption sites over the Fe(100) surface, namely, top(T), bridge (B), and hollow (H) sites as potential catalytic active sites for the molecular and dissociative adsorption of the CH3SH molecule. The molecular adsorption structures are found to occupy either B or T sites with former sites holding higher stability by 0.17 eV. The inclusion of van der Waals corrections refound to slightly alter adsorption energies. For instance, adsorption energies increased by ~ 0.18 and ~ 0.21 eV for B and T structure, respectively, in reference to values obtained by the plain generalized gradient approximation (GGA) functional. A stability ordering of the dissociation products was found to follow the sequence (CH4, S) > (CH3, S, H) > (─SCH3, H) > (─CH3, SH). The differential charge density distributions were examined to underpin prominent electronic contributing factors. Direct fission of C─S bond in the CH3SH molecule attains exothermic values in the range 2.0 to 2.1 eV. The most energetically favorable sites for the surface-mediated fission of the thiol's S─H bond correspond to the structure where the ─SCH3 and H are both situated on hollow sites with an adsorption energy of −2.43 eV. Overall, we found that inclusion of van der Waals functional to change the binding energies more noticeably in case of dissociative adsorption structures. The results presented herein should be instrumental in efforts that aim to design stand-alone Fe desulfurization catalysts. 相似文献
2.
Etienne Brachet Prof. Jean‐Daniel Brion Dr. Mouad Alami Dr. Samir Messaoudi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(45):15276-15280
Unprotected thioglycosides were effective nucleophiles for Ni0‐catalyzed C? S bond‐forming reaction with functionalized (hetero)aryl, alkenyl, and alkynyl halides. The functional‐group tolerance on the electrophilic partner was typically high and the anomeric selectivities of the thioglycosides were high in all cases. The efficiency of this general procedure was well‐demonstrated by the synthesis of 4‐methyl‐7‐thioumbelliferyl‐β‐D ‐cellobioside (MUS‐CB). 相似文献
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Mouad Arrad Mehriban Aliyeva Sérgio M. Vilas-Boas Mohammed Kaddami Hannu Sippola Pekka Taskinen Simão P. Pinho 《Journal of solution chemistry》2018,47(4):774-786
The water activities of manganese nitrate solutions were measured using a humidity sensor instrument up to almost the saturation molality at 298.15 K; the thermodynamic properties of the system were described by the Pitzer model and specific interaction theory (SIT). The evaluation of the ion interaction parameters for the Pitzer model and SIT were carried out using experimental freezing points and osmotic coefficients of manganese nitrate aqueous solutions, collected from the open literature, and the water activity data measured in this work. A set of Pitzer and SIT parameters were estimated using a temperature dependency, that enables us to cover wider temperature ranges, and consequently calculate system properties to higher molalities. Both approaches represent very satisfactorily, and with similar accuracy, the experimental data and the calculated manganese nitrate molal activity coefficients are comparable to those already published for analogous systems. Additionally, the Pitzer model was also able to calculate the ice curve and the solubility branch of manganese nitrate hexahydrate up to a salt solution 6.5 mol·kg?1. 相似文献
4.
An efficient and practical decarboxylative cross-coupling reaction of quinolin-4(1H)-one 3-carboxylic acids with (hetero)aryl halides has been established. Under a bimetallic system of PdBr(2) and silver carbonate, the protocol proved to be general, and a variety of 3-(hetero)aryl 4-quinolinones and related heterocycles, such as 3-aryl-1,8-naphthyridin-4(1H)-ones, 3-arylcoumarins, 3-arylquinolin-2(1H)-ones, and 2-arylchromones, can be prepared in good to excellent yields. 相似文献
5.
Organomanganese chlorides react with β-mono or β,β-bisubstituted ,β-ethylenic aldehydes in the presence of a catalytic amount of copper chloride to give good yields of 1,4-addition products in THF at −30°C. 相似文献
6.
Evelia RasolofonjatovoBret Tréguier Olivier ProvotAbdallah Hamze Estelle MorvanJean-Daniel Brion Mouad Alami 《Tetrahedron letters》2011,52(9):1036-1040
A convenient and efficient procedure for the synthesis of 4-arylchromenes, thiochromenes, and related heterocycles via a four step-sequence has been developed. The first three steps, which involve hydration of alkynes, hydrazones formation, and their Pd-coupling with ortho substituted aryl halides, furnished stereoselectively Z-trisubstituted olefins without any purification of the intermediates generated in each stage. These latter proved to be suitable precursors, in the last step, for the synthesis of the desired heterocycles of biological interest. 相似文献
7.
Impact of DNA Sequence and Oligonucleotide Length on a Polythiophene‐Based Fluorescent DNA Biosensor
Isabelle Charlebois Catherine Gravel Naoual Arrad Maurice Boissinot Michel G. Bergeron Mario Leclerc 《Macromolecular bioscience》2013,13(6):717-722
DNA hybridization is a universal and specific mechanism for the recognition of biological targets. Some cationic polythiophene transducers sensitive to DNA structure have been previously utilized to detect such biomolecules. Further characterization of these systems indicates that both DNA sequence composition and length modulate the biosensor performance. It appears that different repeated sequence patterns cause different conformational changes of the polythiophene, from a more relaxed form to an extremely rigid one. A length difference between the DNA oligonucleotide probe and target has a detrimental effect on the fluorescent signal, but it can be attenuated by changing the sequence composition of the protruding target sequence. This demonstrates that the nature of DNA can be critical for hybridization‐based detection systems.
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Ana M. Mouad Mariana P. Martins Hosana M. Debonsi Ana L. L. de Oliveira Rafael de Felicio Nair S. Yokoya Mutue T. Fujii Claúdia B. A. de Menezes Fabiana Fantinatti‐Garboggini André L. M. Porto 《Helvetica chimica acta》2011,94(8):1506-1514
The biocatalytic reduction of acetophenone derivatives was exploited by using algal biomass from Bostrychia radicans and B. tenella producing exclusively (S)‐2‐phenylethanols with high enantiomeric excess (>99% ee). Bacterial populations associated with algal biomass were identified as the Bacillus genus. This report deals with the first investigations involving the use of marine bacteria associated with B. radicans and B. tenella marine algae for the biocatalytic reduction of acetophenone derivatives. 相似文献
10.
Sophian Sahnoun Samir Messaoudi Jean-François Peyrat Jean-Daniel Brion Mouad Alami 《Tetrahedron letters》2012,53(23):2860-2863
An efficient hydration reaction of various (hetero)aryl nitriles using Cs2CO3 in pyrrolidinone is described. This new metal-free protocol proved to be highly effective and general to synthesize a variety of (hetero)aryl amides. 相似文献