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151.
Takeuchi Masanobu Kageyama Shinji Suzuki Hidekazu Wada Takahiro Notsu Yoshitada Ishii Fumiyoshi 《Colloid and polymer science》2003,281(12):1178-1183
Colloid and Polymer Science - The composition of vehicle on the reversible sol-gel transition temperature in a ternary system made up of methylcellulose (MC), polyethylene glycol (PEG), and citric... 相似文献
152.
Construction of anomalously bent biphenyl structure using conformational properties of calix[4]amide
Masahide Tominaga Terutaka Hatano Masanobu Uchiyama Hyuma Masu Hiroyuki Kagechika Isao Azumaya 《Tetrahedron letters》2006,47(52):9369-9371
C2v-symmetrical cyclic tetramers of aromatic amides were simply synthesized in moderate yield by condensation reaction of N,N′-dimethyl-1,3-phenylenediamine and isophthalic acid derivatives using dichlorotriphenylphosphorane. The calix[4]amides exist in 1,3-alternate structure with cis conformation of tertiary aromatic amides, which were shown to be a versatile scaffold leading to a bowl-shaped macrocyclic compound possessing a anomalously strained structure, a bent hinge angle between two aromatic ring planes of biphenyl moiety, via an intramolecular ligation reaction. 相似文献
153.
154.
Takahide Ishioka Shunsuke Kawamura Tomoyuki Amano Masanobu Taniguchi 《Statistics & probability letters》2009,79(23):2389-2396
This paper discusses an estimation procedure for the spectral density of intrinsic time processes because there has been no argument of the spectral analysis for subordinated processes. Such processes have been proposed in a variety of contexts to describe asset price behavior. They are used when the movement of prices is tied to the number of market transactions, trading volume or the more illusive concept of information arrival. We develop the asymptotic theory for an estimated spectral density of intrinsic time processes and elucidate the asymptotics, which show some interesting structures. Also, numerical studies are given to confirm the results. 相似文献
155.
Osaka I Kondou M Selvapalam N Samal S Kim K Rekharsky MV Inoue Y Arakawa R 《Journal of mass spectrometry : JMS》2006,41(2):202-207
When an intramolecular cavity exists in a molecule, it can trap another chemical species to form a host-guest complex. We examine the formation of such an inclusion complex with cucurbit[n]uril (CBn, n = 6, 7) as the host to trap alkali metal or ammonium ions as the guest, by electrospray ionization mass spectrometry (ESI-MS). The results show that the inclusion complexes are formed between the three-dimensional cylinder of CBn hosts and the guest cations. Selectivity of the complex formation is dependent both on (1) ion-dipole interactions between the cylindrical portal of the CBn hosts and the guest cations and (2) the hydrophobic interactions at the inner cavity of CBn. 相似文献
156.
Ion-exclusion/adsorption chromatography of dimethylsulfoxide (DMSO) and its derivatives, i.e., methanesulfinic acid (MSI), methanesulfonic acid (MSA) and sulfuric acid (SA), was developed in order to clear the decomposition mechanism of DMSO on quality-test of TiO2-photocatalyst in water. The separation was achieved by the adsorption effect for DMSO and ion-exclusion effect for MSI, MSA and SA under optimum conditions, using a weakly acidic cation-exchange resin column with 20 mM succinic acid as the eluent. In this system, DMSO and MSI with UV at 195 nm and MSA and SA with conductivity detection were consecutively determined by single injection and single separation column. This method was used to monitor the artificial decomposition of DMSO induced by a photocatalyst. The concentration of DMSO by active oxygens (e.g., OH radical) generated from surface of photocatalyst was found to be decreased through the stoichiometric reaction in the order of MSI, MSA and SA. 相似文献
157.
Uchiyama M Furuyama T Kobayashi M Matsumoto Y Tanaka K 《Journal of the American Chemical Society》2006,128(26):8404-8405
A versatile preparation method for aromatic zincate compounds through a halogen-zinc exchange reaction using dilithium tetra-tert-butylzincate (tBu4ZnLi2) has been developed. This reagent permits efficient preparation of highly functionalized aromatic zincates, particularly, those with electrophilic functional groups, such as ester, amide, alcohol, and phenol. Halogen-zinc exchange reactions followed by electrophilic trapping (with allyl bromide or benzaldehyde) proved to be a powerful tool for C-C bond formation on functionalized aromatic rings. The functionalized aromatic zincate intermediate was also found to undergo copper- and palladium-catalyzed C-C bond-forming reactions with good yields and high chemoselectivity. 相似文献
158.
Uchiyama M Matsumoto Y Nobuto D Furuyama T Yamaguchi K Morokuma K 《Journal of the American Chemical Society》2006,128(27):8748-8750
The novel directed ortho metalation (DoM) reagents for functionalized aromatic rings, TMP-Zn-ates (R2Zn(TMP)Li (R = Me, 1; tBu, 2)), have been reported to be synthetically useful for the chemo- and regioselective construction of multi-functionalized aromatic compounds. Here, we present the first comprehensive structural and mechanistic investigation by means of X-ray, NMR, and DFT studies on the DoM reaction employing our original TMP-Zn-ate base. The structures of TMP-Zn-ates in solution and in the solid state were determined. The DFT study strongly suggested that the deprotonation involving the TMP ligand on the TMP-Zn-ate is kinetically more favorable than that involving the alkyl ligand, and this view was supported by monitoring of the 13C NMR spectrum of the reaction mixture. 相似文献
159.
Masanobu Nogami Yuichi Sugiyama Yasuhisa Ikeda 《Journal of Radioanalytical and Nuclear Chemistry》2010,283(1):177-180
For the selective extraction of radionuclides from nitrate media, the extraction properties of organopolyphosphine polyoxides
were examined in the form of impregnated adsorbents. It was found that the extraction property of 1,1,3,5,5-pentaphenyl-1,3,5-triphosphapentane
trioxide (PPTPT) for U(VI) is quite unusual with very high values of the distribution ratio in nitric acid solutions of both
low and high concentration ranges, which is not observed for other types of extractants. From the extraction properties for
other metal ions, this type of extracant may be promising for the selective extraction of U(VI) from HNO3 of very low and high concentrations. 相似文献
160.