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351.
Treatment of the mononuclear amide-appended zinc complex [(ppbpa)Zn](ClO4)2 (1(ClO4)2) with Me4NOH.5H2O in CD3CN/D2O (3:1) results in the formation of the deprotonated amide species [(ppbpa-)Zn]ClO4 (2). Upon heating in CD3CN/D2O, this complex undergoes amide hydrolysis to produce a zinc carboxylate product, [(ambpa)Zn(O2CC(CH3)3)]ClO4 (3). X-ray crystallography, 1H and 13C NMR, IR, and elemental analysis were used to characterize 3. The hydrolysis reaction of 1(ClO4)2 exhibits saturation kinetic behavior with respect to the concentration of D2O. Variable-temperature kinetic studies of the amide hydrolysis reaction yielded DeltaH++ = 18.0(5) kcal/mol and DeltaS++ = -22(2) eu. These activation parameters are compared to those of the corresponding amide methanolysis reaction of 1(ClO4)2. 相似文献
352.
Pokhodnya KI Bonner M DiPasquale AG Rheingold AL Her JH Stephens PW Park JW Kennon BS Arif AM Miller JS 《Inorganic chemistry》2007,46(7):2471-2477
MIICl2 (M = Mn, Fe, Co) as their acetonitrile solvates were isolated, and their structural, spectroscopic, and magnetic properties were studied. MCl2(NCMe)2 (M = Fe, Mn) form 1-D chains of octahedral MII ions with four bridging chlorides and two axial MeCN's. The presence of an axial distortion for MFe causes a significant magnetic anisotropy that increases significantly below 150 K; however, chiav [=(chi parallel + 2chi perpendicular)/3] almost coincides with the value obtained on a polycrystalline sample. MnCl2(NCMe)2 is a paramagnet with a weak antiferromagnetic coupling. Annealing FeCl2(NCMe)2 at 55 degrees C forms the monosolvate of FeCl2(NCMe) composition in which two chains collapse into a double chain with formation of Fe-Cl bonding such that half of the mu-Cl's becomes mu3-Cl's. This material orders magnetically below Tc = 4.3 K. For M = Co, paramagnetic tetrahedral [CoCl3(NCMe)]- anions are isolated. 相似文献
353.
Double Transfer of Chirality in Organocopper‐Mediated bis(Alkylating) Cycloisomerization of Enediynes
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Dr. Damien Campolo Dr. Tanzeel Arif Cyril Borie Dr. Dominique Mouysset Dr. Nicolas Vanthuyne Dr. Jean‐Valère Naubron Prof. Michèle P. Bertrand Dr. Malek Nechab 《Angewandte Chemie (International ed. in English)》2014,53(12):3227-3231
An original synthesis of chiral benzofulvenes triggered by organocopper reagents is reported. These enantiopure products are available through a highly chemo‐, regio‐, diastereo‐, and enantioselective bis(alkylating) cycloisomerization process. A double chirality transfer (central‐to‐axial‐to‐central) is observed. 相似文献
354.
Xiaoying Bao Muhammad Arif Malik Daniel G. Norton Vasile B. Neculaes Karl H. Schoenbach Richard Heller Oltea P. Siclovan Susan E. Corah Antonio Caiafa Louis P. Inzinna Kenneth R. Conway 《Plasma Chemistry and Plasma Processing》2014,34(4):825-836
The nonthermal plasma generated in a shielded sliding discharge reactor was used to reform diesel for the hydrocarbon-selective catalytic reduction (HC-SCR) of NOx on Ag/Al2O3 catalysts. Compared with raw diesel, the reformed diesel enhanced the NOx reduction efficiency, mitigated hydrocarbon poisoning of the catalyst and reduced the fuel penalty for the HC-SCR reaction. The NOx conversion values obtained with a commercial Ag/Al2O3 catalyst exceeded that of a 2.0 wt% Ag/Al2O3 catalyst prepared by wet impregnation. A significant amount of NH3 was produced as a by-product during the HC-SCR reaction, which suggests that further NOx conversion enhancement can be achieved by placing a second NH3-SCR catalyst in series with the Ag/Al2O3 catalyst. 相似文献
355.
Ramazan Koçak Giuseppe Borsato Ottorino De Lucchi Arif Daştan 《Helvetica chimica acta》2014,97(4):537-545
New optically active polycyclic ketones 6a – 6d , amenable to a large variety of synthetic applications, have been prepared from readily available 2,3‐dibromonorbornene and analogs (Scheme 2) via desymmetrization with (?)‐ephedrine, followed by hydrolysis under mild acidic conditions. At variance with substrates 4a – 4d , the sterically hindered norbornene derivative 4e reacts with the solvent N‐methylpyrrolidin‐2‐one (NMP) leading to the formation of the unusual cyclopropanoid products 8a and 8b . 相似文献
356.
Kushvar Hajiyeva Arif Ismiev Max Franz Marc Schmidtmann Jürgen Martens Abel Maharramov 《合成通讯》2017,47(22):2031-2035
A series of polyfunctionalized 2-amino-1-methyl-6-(methylthio)-5-nitro-4-aryl-1,4-dihydropyridine-3-carbonitriles have been prepared using a multicomponent condensation reaction between aromatic aldehydes, malononitrile, and (Z) N-methyl-1-(methylthio)-2-nitroethenamine in the presence of Et3N in acetonitrile. 相似文献
357.
Laser short-pulse heating of gold surface is considered and the influence of laser pulse intensity on the temperature and stress fields is investigated. Laser step input pulses with different pulse lengths and the same energy content are employed in the simulations. The electron kinetic theory approach employing thermomechanical coupling is introduced to model the non-equilibrium energy transport in the electron and lattice sub-systems. Thermal stress development in the lattice sub-system and temperature rise in the lattice and electron sub-systems are computed. It is found that electron temperature rises rapidly while lattice site temperature rise is gradual in the early heating period, which is more pronounced for high intensity pulses. Thermal stress component in the axial direction is compressive and its magnitude is considerably less than the yielding limit of the substrate material. 相似文献
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