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By ferricyanide oxidation of 2-(4-methoxyphenyl)phenanthro[9,10-d]imidazole, three new photochromic compounds were obtained. These were 4-ethoxy-4H-, 4-methoxy-4H- and 2-methoxy-2H-phenanthro[9,10-d]imidazoles. These compounds gave the 2-(4-methoxyphenyl)-phenanthro[9,10-d]imidazolyl radical and acetaldehyde or formaldehyde by light irradiation. The imidazolyl radical dimerized gradually in the dark and the dimer dissociated to the imidazolyl radical on heating. 相似文献
4.
Matsuda R Kitaura R Kitagawa S Kubota Y Kobayashi TC Horike S Takata M 《Journal of the American Chemical Society》2004,126(43):14063-14070
In situ synchrotron X-ray powder diffraction patterns of porous coordination polymers [[Cu(2)(pzdc)(2)(bpy)].G] have been measured (pzdc = pyrazine-2,3-dicarboxylate, bpy = 4,4'-bipyridine) (where G = H(2)O for CPL-2 superset H(2)()O, G = benzene for CPL-2 superset benzene, and G = void for the apohost). The structures of apohost and CPL-2 superset benzene were determined from Rietveld analysis. Adsorption of benzene in the channels induced a remarkable contraction in the crystal (b axis; 6.8%, volume; 4.9%), although the channels were occupied by the benzene molecules. This crystal transformation provides a new pore structure that is well suited for benzene molecules, and we denote it as a "shape-responsive fitting" transformation. This type of pore gives rise to a new guideline: frameworks can be composed of flexible motifs that are linked via strong bond and/or stiff motifs that are connected via weaker bonds. 相似文献
5.
Masao Tomoi Satoru Ishigaki Yasushi Arita Hiroshi Kakiuchi 《Journal of polymer science. Part A, Polymer chemistry》1988,26(8):2251-2261
Polystyrene-bound 4-(1-pyrrolidino)pyridine moieties were prepared by the reaction of chloromethylated polystyrene resins with pyrrolidinopyridine derivatives containing hydroxyl groups. The supported amines were effective catalysts for acylations of tert-alcohols or enols, acylrearrangements, and diester synthesis from epoxides and anhydrides. Some of the low ring-substituted (8–15%) catalysts exhibited high activity comparable to that of 4-(N,N-dimethylamino)pyridine, though the activity was a little lower than that of 4-(1-pyrrolidino)pyridine. The recovered catalysts can be re-used, except for acyl rearrangements, without significant decrease in activity. 相似文献
6.
M Nishikata A Nakai H Fushida K Miyake T Arita S Kitagawa M Kunitomo K Iseki K Miyazaki 《Chemical & pharmaceutical bulletin》1992,40(5):1341-1342
A method was developed for semi-preparative scale enantioseparation of racemic homochlorcyclizine (HCZ) by high performance liquid chromatography (HPLC) on Chiralcel OD column. The best resolution was achieved using an eluent composed of n-hexane plus 0.2 M isopropylamine. By this method, about 5.0 mg of racemic HCZ could be resolved completely in one run. The optical purity of the enantiomers were both greater than 99.9%. The studies of antihistamine activity on guinea pig ileum demonstrated that l-HCZ is significantly more potent than d- and racemic HCZ. The pharmacokinetics of d- and l-HCZ after oral administration to rats also differed. The successful resolution of racemic HCZ permits comparison of the pharmacokinetics and antihistamine activity of the enantiomers. 相似文献
7.
Kohara T Koyama T Fujimura M Tanaka H Maeda J Fujimoto T Yamamoto I Arita M 《Chemical & pharmaceutical bulletin》2002,50(6):818-821
The oxidation behavior of Y-931, a potent atypical antipsychotic drug, was compared with that of clozapine and olanzapine. In two enzymatic systems (horseradish peroxidase (HRP)/glutathione (GSH) and HRP/H(2)O(2)/GSH) which generate thiyl radicals, clozapine markedly strengthened the electron paramagnetic resonance (EPR) signal for the radical. Olanzapine, Y-931 and the major metabolites (compounds 1-3) had no or minimal effect on the intensity of this signal. In addition, the redox potential values for the three derivatives were in accord with the EPR spin trapping results. In toxicological experiments in human leukocytes, a concentration-dependent toxicity was observed when neutrophils were incubated with clozapine (1-10 micromol/l) and H(2)O(2) (1 mmol/l). However, Y-931 and olanzapine did not show remarkable toxicity under the conditions. 相似文献
8.
We develop a fully calibrated positive mathematical programming model for Hawaii's local food systems—which captures the production and the consumer sides of the market. Then we use the model to assess two proposed policies—a general excise tax (GET) exemption on locally produced foods, and an investment in agricultural infrastructure. For the GET exemption case, our results indicate an economic gain of $118 per $100 cost. On the other hand, an investment in 1,200 acres of land injected to support local production may generate an economic gain of up to $357 per $100 annual cost of the investment. However, these estimates should be considered preliminary, and thus viewed with caution. Although the model is used to capture Hawaii's local food systems, we believe that our model is generalizable and can be adopted by other economies to assess their respective food localization policies. Recommendations for Resource Managers
- Local food policies need to be based on quantitative terms instead of mere armchair speculation because often their potential outcomes may vary significantly.
- The current modeling framework demonstrates the potential of using positive mathematical programming (PMP) in capturing the intricacies of local food systems. However, this exploratory exercise should be viewed as preliminary in nature and the ensuing results were taken with caution because many important factors such as labor availability may have been left out.
- Thus, further model refinements are necessary to better capture the complexities of local food systems such as farm heterogeneity, availability of farm labor, water availability, and interisland transportation of farm products in the case of Hawaii.
9.
Let f : S(E) → S(B) be a surjective isometry between the unit spheres of two weakly compact JB*-triples not containing direct summands of rank less than or equal to 3. Suppose E has rank greater than or equal to 5. Applying techniques developed in JB*-triple theory, we prove that f admits an extension to a surjective real linear isometry T : E → B. Among the consequences, we show that every surjective isometry between the unit spheres of two compact C*-algebras A and B, without assuming any restriction on the rank of their direct summands(and in particular when A = K(H) and B = K(H′)), extends to a surjective real linear isometry from A into B. These results provide new examples of infinite-dimensional Banach spaces where Tingley's problem admits a positive answer. 相似文献
10.
Toshihiko Arita Jungwoo Yoo Tadafumi Adschiri 《Journal of nanoparticle research》2010,12(7):2567-2578
Decanoic acid self-assembled monolayer (SAM) in the quasi-crystalline state was prepared on the surface of the cubic CeO2 nanoparticles (6.5 ± 1.1 nm) by hydrothermal synthesis. The purification method to obtain quasi-crystalline SAM without residual
(free) decanoic acid was developed. The SAM was carefully washed (purified) and characterized carefully by FT-IR, TG, DSC,
and NMR. The obtained results showed that good agreement with the property of the dry state SAM. The solution state properties
of the SAM were also examined by the CeO2 nanoparticles. It turned out that the quasi-crystalline SAM could be swollen by its good solvents, cyclohexane, and chloroform;
however, the quasi-crystalline SAM showed that a size exclusion effect to the solvent, trans-decalin. In addition, it turned out that the molecular motion of the decanoic acids in the SAM was highly restricted even
in the swollen state depending on the distance from the grafting point to the CeO2 surface. The strong osmosis was also observed. The solvent molecules were not easily released from the SAM even after the
solvent molecules outside of the SAM were frozen. 相似文献