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91.
Normanskaja Yu. V. Borisenko O. D. Beloborodov I. B. Avetisyan A. I. 《Doklady Mathematics》2022,105(3):187-206
Doklady Mathematics - The LingvoDoc system ( http://lingvodoc.ispras.ru ) provides a service for collaborative language documentation and computations on the collected data. This software system... 相似文献
92.
Yukimasa Aida Juntaro Nogami Dr. Haruki Sugiyama Prof. Dr. Hidehiro Uekusa Prof. Dr. Ken Tanaka 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(55):12579-12588
The enantioselective synthesis of polycyclic aromatic hydrocarbon (PAH)-based planar chiral cyclophanes was achieved for the first time by the rhodium-catalyzed intramolecular regio- and enantioselective [2+2+2] cycloaddition of tethered diyne-benzofulvenes followed by stepwise oxidative transformations. The thus synthesized planar chiral bent cyclophanes, that possess bent p-terphenyl- and 9-fluorenone-cores, were converted to 9-fluorenol-based ones with excellent ee values of >99 % by diastereoselective 1,2-reduction. These 9-fluorenol-based cyclophanes exhibited high fluorescence quantum yields, which were significantly higher than that of an acyclic reference molecule (78–82 % vs. 48 %). The bending effect on the chiroptical property was also examined, which revealed that the anisotropy factors (gabs values) for electronic circular dichroism (ECD) of these 9-fluorenol-based planar chiral bent cyclophanes increase as the tether length becomes shorter. 相似文献
93.
Aida Contreras-Ramirez Dr. Bryan E. Tomlin Gregory S. Day Prof. Dr. Abraham Clearfield Prof. Dr. Hong-Cai Zhou 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(28):6185-6194
Nanosized α-zirconium phenylphosphonate particles were successfully prepared by the reaction between different zirconium sources and molten phenylphosphonic acid in the absence of solvent. The resultant nanoplates exhibit particle sizes in the range of 15 to 30 nm. The use of a topotactic anion exchange method starting from α-zirconium phosphate instead resulted in the generation of 15 to 180 nm plates, while also resulting in nanoparticles with a higher degree of crystallinity. The topotactic anion exchange of the phosphate groups by phenylphosphonate groups could be performed to completion when performed in molten phenylphosphonic acid. Characterization of both the final products as well as the individual steps in the anion exchange were performed by powder XRD, fast neutron activation analysis, TGA, FTIR spectroscopy, TEM, solid-state NMR and XPS. 相似文献
94.
Aboul-Enein Mohamed N. El-Azzouny Aida A. Maklad Yousreya A. Ismail Mohamed A. Ismail Nasser S. M. Hassan Rasha M. 《Research on Chemical Intermediates》2015,41(6):3767-3791
Research on Chemical Intermediates - A series of novel safinamide derivatives were synthesized and biologically evaluated for their anticonvulsant activity against maximal electroshock seizure... 相似文献
95.
Vladimir I. Bakhmutov Aida Contreras-Ramirez Hannah Drake Hong-Cai Zhou 《Magnetic resonance in chemistry : MRC》2022,60(6):541-553
Solid-state NMR experiments on 2H, 31P, 13C, and 1H nuclei, including 31P T1, 1H T1, and 1H T1ρ measurements, as well as on the kinetics of proton-phosphorus cross-polarization have been performed to characterize the crystalline and amorphous α-zirconium phosphates, which were intercalated with D2O and/or CD3OD. The 13C{1H} CP MAS NMR experiment performed for compound 1-CD 3 OD (Zr (HPO4)2 . 0.2CD3OD) with carbon cross-polarization via protons of phosphate groups has provided a prove that the methanol was intercalated into the interlayer spaces of this compound. The variable-temperature 2H solid-echo MAS NMR spectra of intercalated compounds demonstrated that the methanol molecules, in contrast to the mobile water, were immobile, keeping, however, free CD3 rotations around the C3-axis. It has been demonstrated that the intercalated species, D2O and CD3OD, do not affect the high-frequency motions of the phosphate groups. By utilizing local structural models that satisfy the constraints of the experimental data, it has been suggested that the immobile methanol molecules are located in the cavity between two neighboring layers of the zirconium phosphates. Thus, the present work illustrates the reliable criteria in a comprehensive NMR approach to structural and dynamic studies of such systems. 相似文献
96.
We describe here a rapid process for the preparation of new 9-chloromethyl-12-aryl-10,12-dihydrobenzo[5,6]chromeno[2,3-d]pyrimidin-11-ones 5a-d and 10-chloromethyl-7-aryl-7,9-dihydrobenzo[7,8]chromeno[2,3-d]pyrimidin-8-ones 6a-d by two different methods utilizing microwave irradiation. This methodology provides better yields(72%–80%) and high purity of the title compounds. 相似文献
97.
Francisco Fraga López Eva C. Vázquez Barreiro Aida Jover Julio A. Seijas Francisco Meijide José Vázquez Tato 《Polymer Science Series B》2018,60(4):481-496
In this work we introduce the zinc 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphine (ZnTPyP) macrocycle as a crosslinking agent of the epoxy resin BADGE n = 0. NMR, TEM and FTIR confirm that both homopolymerization and heteropolymerization (resulting in the formation of a pyridone) are taken place. DSC evidences two exothermic signals at 170 and 290°C, with enthalpy values of 262.3 and–20.7 J/g, respectively. Crystal powder diffraction supports that the second one corresponds to a physical process. The introduction of the ZnTPyP into the epoxy network improves the thermal stability of the material, which, although very weakly, shows ferromagnetic properties. 相似文献
98.
Irena S. Akhrem Dzul’etta V. Avetisyan Lyudmila Afanas’eva Sergei V. Vitt Pavel V. Petrovskii Alexander Orlinkov 《Tetrahedron letters》2008,49(8):1399-1404
Alkanes (or cycloalkanes) and CO in the presence of superelectrophilic systems CX4·2AlBr3 (X = Cl, Br) have been applied for the first time as equivalents of acylium salts in one-pot selective syntheses of amides from amines. 相似文献
99.
K. L. Avetisyan 《Potential Analysis》2008,29(1):49-63
We study anisotropic mixed norm spaces h(p,q,α) consisting of n-harmonic functions on the unit polydisc of by means of fractional integro-differentiation including small 0 < p < 1 and multi-indices α = (α
1,...,α
n
) with non-positive α
j
≤ 0. As an application, two different Bloch spaces of n-harmonic functions are characterized.
相似文献
100.
Li WS Yamamoto Y Fukushima T Saeki A Seki S Tagawa S Masunaga H Sasaki S Takata M Aida T 《Journal of the American Chemical Society》2008,130(28):8886-8887
For tailoring solution-processable optoelectronic thin films, a rational strategy with amphiphilic molecular design is proposed. A donor-acceptor dyad consisting of an oligothiophene and C60, when modified with a hydrophilic wedge on one side and a paraffinic wedge on the other (1Amphi), forms over a wide temperature range a photoconducting smectic A liquid crystal having bicontinuous arrays of densely packed donor and acceptor units. In contrast, when modified with only paraffinic wedges (1Lipo), the dyad forms a smectic A liquid crystalline mesophase, which however is poorly conductive. As indicated by an absorption spectral feature along with a synchrotron radiation small-angle X-ray scattering profile, 1Lipo in the lamellar structure does not adopt a uniform head/tail orientation. Such defective donor and acceptor arrays likely contain a large number of trapping sites, leading to short-lived charge carriers, as observed by a flash photolysis time-resolved microwave conductivity study. 相似文献