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661.
Miyuki Narita Fumio Hamada 《Journal of inclusion phenomena and macrocyclic chemistry》2002,44(1-4):335-340
Fluorogenic active host labeled at the upper and lower rims of -cyclodextrin, namely, mono-3A-deoxy-3A-pyrenebutylamido-6X-O-mono-pyrenebutylate-mono-altro--cyclodetrin (mixture
-1,X = A, B, C, D, E, F, G, or H), has been synthesized in order to investigate their host-guest complexation with steroidal compoundsusing fluorescence spectra. Monomer and excimer fluorescence was observed for mixture host. Inclusion of a guest molecule in the cyclodextrin cavity resultedin increased monomer fluorescence and decreased excimer fluorescence. The extent of monomerand excimer fluorescence variations ofmixture -1 with the guestwas used as an indication for the sensing ability. The guest inducedfluorescence changes were measured for 10-7 M solutions of mixture
-1.The values I/I
0
, where I
0
and I are fluorescence intensities in the absence and presence of a guest, respectively, and I is I
0
- I, were then used to describe the sensing ability. 相似文献
662.
Guo-qing Zheng Yoshio Kitaoka Kunisuke Asayama K. Hamada H. Yamauchi S. Tanaka 《Physica C: Superconductivity and its Applications》1996,260(3-4):197-210
63Cu, 17O and 205Tl NMR have been performed in the high-Tc superconductor Tl2Ba2Ca2Cu3O10 whose Tc(max) is 127 K. The hole densities at Cu and oxygen sites in the CuO2 plane have been extracted from the nuclear quadrupole frequency νQ. The striking feature is that the Cu holes are significantly transferred to oxygen site due to strong hybridization between Cu and oxygen. From an analysis of T1 and T2G, it has been found that the spectral weight of the spin fluctuation is transferred to higher energy compared to YBa2Cu3O7, while the magnetic correlation length ξ does not differ much. Thus, it is suggested that the higher Tc is due to higher characteristic energy of spin fluctuations, i.e. the superconductivity is spin fluctuation mediated. The superconducting properties are consistently explained by a d-wave superconductivity model with a finite density of states (DOS) at the Fermi level. We show that the disorder of the Ca/TlO layer caused by the partial inter-substitution of Tl and Ca is responsible for the potential scattering to produce such a DOS. It is found that if such a potential scattering were absent, Tc would go up to 132 K which is quite close to the record Tc realized in the Hg based compound. 相似文献
663.
Transition Metal Chemistry - The composition and stability of binary and ternary complexes of Cd(II) with phthalate and adipate anions as primary ligands and imidazole as a secondary ligand have... 相似文献
664.
Nakata K Takeda T Mihara J Hamada T Irie R Katsuki T 《Chemistry (Weinheim an der Bergstrasse, Germany)》2001,7(17):3776-3782
(Nitrosyl)(salen)ruthenium(II) complex 1 was found to serve as an efficient catalyst for the epoxidation of conjugated olefins under photoirradiation, with 2,6-dichloropyridine N-oxide (2) or tetramethylpyrazine N,N'-dioxide as a stoichiometric oxidant. High enantioselectivity was achieved irrespective of the substitution pattern of olefins. The choice of solvent depends on stability of the resulting epoxides: high enantioselectivity is generally observed in the reaction with ethereal solvents, but use of benzene is recommended when the resulting epoxides are acid-sensitive. 相似文献
665.
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667.
In this article, attention is directed to molecular recognition by micellar aggregates made with ionic surfactants involving directed interactions of substrates. Particular emphasis is placed on chiral recognition of enantiomers by hydrogen bonding functionalities incorporated in hydrophobic micellar interior. Hydrophobic properties within micelles, the ordering of their polar headgroups containing chiral functionalities essential for the recognition and the cessation of micellar kinetic association-dissociation with polymerization and immobilization of the surfactants on the support are discussed. 相似文献
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