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181.
Yuuki Shimakawa 《Tetrahedron letters》2010,51(13):1786-457
A simple and efficient one-pot procedure for the synthesis of α-diketones from aldehydes via benzoin condensation under the influence of a catalytic amount of azolium salt combined with DBU has been developed. Thus, aldehyde was allowed to react with the azolium salt/DBU catalytic system at room temperature, and then the reaction mixture was heated to 70 °C under air atmosphere to afford the corresponding 1,2-diketone in good yield. This would be an efficient alternative method of synthesizing α-diketones from aldehydes under metal-free conditions. 相似文献
182.
Ge M Nagel U Hüvonen D Rõõm T Mamone S Levitt MH Carravetta M Murata Y Komatsu K Lei X Turro NJ 《The Journal of chemical physics》2011,135(11):114511
We report on the dynamics of two hydrogen isotopomers, D(2) and HD, trapped in the molecular cages of a fullerene C(60) molecule. We measured the infrared spectra and analyzed them using a spherical potential for a vibrating rotor. The potential, vibration-rotation Hamiltonian, and dipole moment parameters are compared with previously studied H(2)@C(60) parameters [M. Ge, U. Nagel, D. Hüvonen, T. R??m, S. Mamone, M. H. Levitt, M. Carravetta, Y. Murata, K. Komatsu, J. Y.-C. Chen, and N. J. Turro, J. Chem. Phys. 134, 054507 (2011)]. The isotropic part of the potential is similar for all three isotopomers. In HD@C(60), we observe mixing of the rotational states and an interference effect of the dipole moment terms due to the displacement of the HD rotation center from the fullerene cage center. 相似文献
183.
184.
Yue-Wei Ge Shu Zhu Kohei Kazuma Sheng-Li Wei Kayo Yoshimatsu Katsuko Komatsu 《Analytical and bioanalytical chemistry》2016,408(13):3555-3570
185.
186.
Crystals of salol were grown by the Czochralski method in three different pulling directions to examine the crystallographic orientation effect of the seed. They were characterized by the etch pit method and X-ray projection topography. It was found that the dislocation density was 2 × 103−1 × 104/cm2 and that the configuration of dislocations was straight. The running directions of dislocations strongly depend on the pulling directions; i.e., [11 0] and [1 10] for the crystal grown in [100] axis, [11 0], [1 10] and [110] for the crystal pulled along [112] axis and [010] for [010] axis crystal. 相似文献
187.
188.
Masami Yonemura Yuuki Nakamura Naoki Usuki Hisashi kawa 《Journal of Chemical Sciences》2000,112(3):291-310
This paper discusses coordination-position isomeric MIICuII and CuIIMII complexes, using unsymmetric dinucleating macrocycles (Lm;n)2− ((L2;2)2−, (L2;3)2− and (L2;4)2−) that comprise two 2-(N-methyl)-aminomethyl-6-iminomethyl-4-bromo-phenonate entities, combined through the ethylene chain
(m = 2) between the two amine nitrogens and through the ethylene, trimethylene or tetramethylene chain(n = 2, 3 or 4) between the two imine nitrogens. The macrocycles have dissimilar N(amine)2O2 and N(imine)2O2 metal-binding sites sharing the phenolic oxygens. The reaction of the mononuclear CuII precursors, [Cu(L2;2)], [Cu(L2;2)] and [Cu(L2;2)], with a MII perchlorate and a MII acetate salt formed (acetato)MIICuII complexes: [CoCu(L2;2)(AcO)]ClO4·0.5H2O] (1), [NiCu(L2;2) (AcO)]ClO4 (2), [ZnCu(L2;2) (AcO)]ClO4 (3), [CoCu(L2;3)(AcO)]ClO4·0.5H2O (4), [NiCu(L2;3)(AcO)]ClO4 (5), [ZnCu(L2;3)(AcO)]ClO4·0.5H2O (6), [CoCu(L2;4)(AcO)(DMF)]ClO4 (7), [NiCu(L2;4) (AcO)]ClO4·2DMF (8) and [ZnCu(L2;4)(AcO)]ClO4 (9) (the formulation [MaMb (Lm;n)]2+ means that Ma resides in the aminic site and Mb in the iminic site). The site selectivity of the metal ions is demonstrated by X-ray crystallographic studies for 2·MeOH,3,5,7, and9. An (acetato)CuIIZnII complex, [CuZn(L2;3)(AcO)]ClO4 (10), was obtained by the reaction of [PbCu(L2;3)]-(ClO4)2 with ZnSO4·4H2O, in the presence of sodium acetate. Other complexes of the CuIIMII type were thermodynamically unstable to cause a scrambling of metal ions. The Cu migration from the iminic site to the aminic
site in the synthesis of10 is explained by the ‘kinetic macrocyclic effect’. The coordination-position isomers,6 and10, are differentiated by physicochemical properties. 相似文献
189.
Nishida A Yamada M Kanazawa T Takashima Y Ouchi K Okada H 《Chemical & pharmaceutical bulletin》2010,58(11):1480-1486
To evaluate the usability of silk protein (sericin, SC) as a sustained-release material, the physicochemical properties of SC and the release profiles of model drugs from SC gel, sponge and film were studied. Heat aids the dissolution of SC. The molecular weight of SC tended to decrease as the heating temperature and heating time increased. The gel and sponge formed by SC were moldable and consisted of high molecular weight SC polymers (250 kDa and about 400 kDa). SC film was easily broken and exhibited elastic distortion. The addition of moisture-retaining plasticizer (glycerin and sorbitol) improved the film-forming characteristics of SC. The results suggested that SC is practical as a moldable gel and sponge, and as a tensible film. To evaluate the release profiles of small molecules, fluorescein isothiocyanate-dextran ((1) FD4, 4 kDa and (2) FD70, 70 kDa) were used as two model drugs with significantly different molecular weights, and fluorescein isothiocyanate-albumin ((3) FA, 66 kDa) was used as a charged drug. Each was formulated in SC gel, sponge and film. In each preparation, the release rate of the model drugs tended to be FA相似文献
190.
Kuwahara M Takano Y Kasahara Y Nara H Ozaki H Sawai H Sugiyama A Obika S 《Molecules (Basel, Switzerland)》2010,15(11):8229-8240
Recently, KOD and its related DNA polymerases have been used for preparing various modified nucleic acids, including not only base-modified nucleic acids, but also sugar-modified ones, such as bridged/locked nucleic acid (BNA/LNA) which would be promising candidates for nucleic acid drugs. However, thus far, reasons for the effectiveness of KOD DNA polymerase for such purposes have not been clearly elucidated. Therefore, using mutated KOD DNA polymerases, we studied here their catalytic properties upon enzymatic incorporation of nucleotide analogues with base/sugar modifications. Experimental data indicate that their characteristic kinetic properties enabled incorporation of various modified nucleotides. Among those KOD mutants, one achieved efficient successive incorporation of bridged nucleotides with a 2'-ONHCH?CH?-4' linkage. In this study, the characteristic kinetic properties of KOD DNA polymerase for modified nucleoside triphosphates were shown, and the effectiveness of genetic engineering in improvement of the enzyme for modified nucleotide polymerization has been demonstrated. 相似文献