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91.
The first enantiospecific total synthesis of the tricyclic sesquiterpene (+)-seychellene, starting from (R)-carvone via (S)-3-methylcarvone, has been accomplished employing a combination of an intermolecular Michael addition-intramolecular Michael addition sequence and an intramolecular alkylation reaction for the generation of the two vicinal quaternary carbon atoms. 相似文献
92.
Summary 0.02 g/0.2 ml of potassium ferricyanide can be detected on a spot plate by utilising its catalytic effect on the reaction of cerium (III) with sulphosalicylic acid. A probable mechanism is discussed.
Zusammenfassung Die katalytische Wirkung von Hexacyanoferrat(III) auf die Reaktion zwischen Cer(III) und Sulfosalicylsäure wird zur einem empfindlichen Tüpfelnachweis für [Fe(CN)6]3– benutzt. Noch 0,02 g/0,2 ml können nachgewiesen werden. Der Reaktionsmechanismus wird diskutiert.相似文献
93.
Summary Three new bifunctional phosphinoamide ligands of the type Ph2PCH2C(O)NHR (R = H, HDPA; Me, MDPA; Ph, PDPA) were prepared and characterized. Their ruthenium(II) complexes prepared from two different precursors, RuCl2-(DMSO)4 and RuCl2(PPh3)3, are of similar composition and correspond to the formula, [RuCl(L)2(P-O)2]Cl (L = DMSO/PPh3; phosphinoamide). However, RuCl3-(AsPh3)2(MeOH) reacts with the phosphinoamide to yield a reduced product of the cis-RuCl2(P-O)2 type. The ligands and complexes were characterized by mass, i.r. and n.m.r. spectroscopy. Possible stereochemistries for the complexes are proposed. 相似文献
94.
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96.
P. Ramesh Kumar M. Venkateswarlu Manjusri Misra Amar K. Mohanty N. Satyanarayana 《Ionics》2013,19(3):461-469
Lithium manganese phosphate (LiMnPO4) nanorods were synthesized using the modified polyol method. Polyvinylpyrrolidone was used as a stabilizer to control the shape and size of LiMnPO4 nanorods. Resin coating process was used to coat the carbon over the LiMnPO4 nanorods. X-ray diffraction and Fourier transform infrared spectroscopy results showed the formation of LiMnPO4 crystalline phase. The TEM image shows a uniform coating of the nano size (2.3 nm) carbon over the surface of LiMnPO4 nanorods and the EDS spectrum of the carbon-coated LiMnPO4 nanorods confirming the presence of carbon element along with the other Mn, P, and O elements. Impedance measurements were made on pure and carbon-coated LiMnPO4 nanorods, and their conductivities were evaluated by analyzing the measured impedance data using the WinFIT software. More than two orders of magnitude of conductivity enhancement was observed in the carbon-coated LiMnPO4 nanorods compared to pure ones, and the conductivity enhancement may be attributed to the presence of carbon over LiMnPO4 nanorods. Temperature dependence of conductivity and ac conductivity were calculated using impedance data of pure and carbon-coated LiMnPO4 nanorods. CR2032 type lithium ion coin cells were fabricated using pure and carbon-coated LiMnPO4 nanorods and characterized by measuring charge–discharge cycles between 2.9 and 4.5 V at room temperature. More than 25 % of improved capacity was achieved in the carbon-coated LiMnPO4 nanorods when compared to pure ones synthesized using modified polyol and resin coating processes. 相似文献
97.
R. Srinivasulu P. V. V. Satyanarayana K. Ravi Kumar 《Russian Journal of General Chemistry》2013,83(12):2419-2422
Treatment of tetrahydropyranyl (THP) ethers with zinc triflate in methanol provides a simple and efficient process for deprotection of these ethers and the parent alcohols are obtained in excellent yields. 相似文献
98.
A simple and new synthetic approach to various analogues of Irbesartan is described. 相似文献
99.
Smeer Durani M. Krishnakumar K. Satyanarayana 《Journal of Radioanalytical and Nuclear Chemistry》2012,294(2):215-220
A simple, effective and low cost solid phase extraction procedure was standardized for the trace and ultra-trace level determination of rare earth impurities, such as, Ce, Dy, Sm, Gd, Eu, Er etc. which act as neutron poisons, in nuclear grade uranium oxide (U3O8?>?99.9% by weight). The method involves selective separation of these elements as their fluorides with the help of activated charcoal from major uranium matrix followed by determination by ICP-MS and high resolution ICP-OES. The residual uranium content of the solution was <10???g/mL. The recovery of REEs ranges from 85 to 105%. The method was validated with nuclear grade uranium oxide standards CRM-I to CRM-V (BARC, Mumbai, India) in addition to some synthetic standards. The RSD of the method was ±12% (n?=?3). 相似文献
100.
A series of deoxycholic and cholic acid‐derived oligomers were synthesized and their ability to extract hydrophilic dye molecules of different structure, size, and functional groups into nonpolar media was studied. The structure of the dye and “dendritic effect” in the extraction process was examined using absorption spectroscopy and dynamic light scattering (DLS). The efficiency of structurally preorganized oligomers in the aggregation process was evaluated by 1‐anilinonaphthalene‐8‐sulfonic acid (ANS) fluorescence studies. The possible formation of globular structures for higher‐generation molecules was investigated by molecular modeling studies and the results were correlated with the anomaly observed in the extraction process with this molecule. The ability of these molecules for selective extraction of specific dyes from blended colors is also reported. 相似文献