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991.
A. E. Kretov A. P. Momsenko A. S. Bespalyi Yu. A. Levin 《Chemistry of Heterocyclic Compounds》1970,4(1):78-79
The condensation of 2-hydroxy-3-mercaptoquinoline-4-carboxylic acid with isothiocyanates has given 2-alkyl-5-hydroxy-1-oxodihydro-1, 3-thiazino [6, 5-c]quinoline-3-thiones. The structure of the compounds obtained has been shown by reactions with semicarbazide, thiosemicarbazide, and by hydrolysis and oxidation. 相似文献
992.
Weizmann Y Patolsky F Lioubashevski O Willner I 《Journal of the American Chemical Society》2004,126(4):1073-1080
The ultra-sensitive magneto-mechanical detection of DNA, single-base-mismatches in nucleic acids, and the assay of telomerase activity are accomplished by monitoring the magnetically induced deflection of a cantilever functionalized with magnetic beads associated with the biosensing interface. The analyzed M13phi DNA hybridized with the nucleic acid-functionalized magnetic beads is replicated in the presence of dNTPs that include biotin-labeled dUTP. The resulting beads are attached to an avidin-coated cantilever, and the modified cantilever is deflected by an external magnetic field. Similarly, telomerization of nucleic acid-modified magnetic beads in the presence of dNTPs, biotin-labeled dUTP, and telomerase from cancer cell extracts and the subsequent association of the magnetic beads to the cantilever surface results in the lever deflection by an external magnetic field. M13phi DNA is sensed with a sensitivity limit of 7.1 x 10(-20) M by the magneto-mechanical detection method. 相似文献
993.
2, 5-Diphenyl-1, 3, 4-oxadiazoles are shown to react with aromatic amines on heating, to give 2, 5-diphenyl-4-aryl-1, 2, 4-triazoles. 相似文献
994.
995.
996.
V. A. Mamedov I. Z. Nurkhametova A. T. Gubaidullin I. A. Litvinov Ya. A. Levin 《Russian Chemical Bulletin》2005,54(2):441-444
Condensation of methyl phenylchloropyruvate with 4-phenylthiosemicarbazide proceeds as the Bose reaction to form 5-methoxycarbonyl-6-phenyl-2-phenylimino-6H-1,3,4-thiadiazine, which is hydrolyzed to give carboxylic acid. In the presence of polyphosphoric acid, the latter undergoes intermolecular cyclodehydration accompanied by sulfur extrusion to yield dipyrazolo [1,5-a,1′,5′d]pyrazine.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 432–435, February, 2005. 相似文献
997.
Oleg L. Eliseev Tatyana N. Bondarenko Sergey N. Britvin Polina P. Khodorchenko Albert L. Lapidus 《Mendeleev Communications》2018,28(3):264-266
Rhodium-catalysed hydroformylation of styrene and aliphatic olefins under biphasic conditions in the presence of watersoluble 1,4,7-triaza-9-phosphatricyclo[5.3.2.14,9]tridecane (CAP) chemoselectively affords aldehydes. Multiple catalyst reuse without loss in performance is demonstrated. 相似文献
998.
Supramolecular Organization of Dye Molecules in Zeolite L Channels: Synthesis,Properties, and Composite Materials 下载免费PDF全文
Dr. Pengpeng Cao Dr. Oleg Khorev Dr. André Devaux Lucie Sägesser Dr. Andreas Kunzmann Prof. Achim Ecker Prof. Robert Häner Dr. Dominik Brühwiler Prof. Gion Calzaferri Prof. Peter Belser 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(12):4046-4060
Sequential insertion of different dyes into the 1D channels of zeolite L (ZL) leads to supramolecular sandwich structures and allows the formation of sophisticated antenna composites for light harvesting, transport, and trapping. The synthesis and properties of dye molecules, host materials, composites, and composites embedded in polymer matrices, including two‐ and three‐color antenna systems, are described. Perylene diimide (PDI) dyes are an important class of chromophores and are of great interest for the synthesis of artificial antenna systems. They are especially well suited to advancing our understanding of the structure–transport relationship in ZL because their core fits tightly through the 12‐ring channel opening. The substituents at both ends of the PDIs can be varied to a large extent without influencing their electronic absorption and fluorescence spectra. The intercalation/insertion of 17 PDIs, 2 terrylenes, and 1 quaterrylene into ZL are compared and their interactions with the inner surface of the ZL nanochannels discussed. ZL crystals of about 500 nm in size have been used because they meet the criteria that must be respected for the preparation of antenna composites for light harvesting, transport, and trapping. The photostability of dyes is considerably improved by inserting them into the ZL channels because the guests are protected by being confined. Plugging the channel entrances, so that the guests cannot escape into the environment is a prerequisite for achieving long‐term stability of composites embedded in an organic matrix. Successful methods to achieve this goal are described. Finally, the embedding of dye–ZL composites in polymer matrices, while maintaining optical transparency, is reported. These results facilitate the rational design of advanced dye–zeolite composite materials and provide powerful tools for further developing and understanding artificial antenna systems, which are among the most fascinating subjects of current photochemistry and photophysics. 相似文献
999.
1000.
S. F. Levin 《Physics of Atomic Nuclei》2015,78(13):1528-1533
The problems arising from the incorrect formulation of measuring problems of identification for cosmological models and violations of conditions of applicability of statistical methods are considered. 相似文献