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51.
Yamanaka N Kawano R Kubo W Kitamura T Wada Y Watanabe M Yanagida S 《Chemical communications (Cambridge, England)》2005,(6):740-742
Use of a new ionic liquid crystal, 1-dodecyl-3-methylimidazolium iodide, and iodine as an electrolyte of dye-sensitized solar cells leads to a high short circuit photocurrent density and a high light-to-electricity conversion efficiency, due to a self-assembled structure of the imidazolium cations, resulting in high conductivity of the electrolyte. 相似文献
52.
Kazuyoshi Yano Hiroshi Yoshitake Uwe T. Bornscheuer Rolf D. Schmid Kazunori Ikebukuro Kenji Yokoyama Yuzo Masuda Isao Karube 《Analytica chimica acta》1997,340(1-3):41-48
Piezoelectric quartz crystal sensors were developed using lipids with various properties for highly sensitive detection of chemical vapors. Lipids with varying lengths of alkyl chains were coated onto 10 MHz AT-cut quartz crystal resonators and the response of these modified crystals to chemical vapors were measured. It was shown that hydrophilic compounds, such as ethanol and methanol, could be recognized efficiently by lipids having shorter alkyl chains, whereas lipids with longer alkyl chains showed affinity to more hydrophobic vapors, such as toluene, hexane and cyclohexane. Frequency changes caused by adsorption of alcohols could be enhanced when cholesterol was co-immobilized in the lipid layer. To confirm the assumption that the sensor-response might be affected by the properties of lipids derived from acyl chains, we have examined the effects of two types of newly synthesized unusual lipids on sensor response. When lipids having one triple bond each at different positions on their alkyl chains were coated onto quartz crystals separately, lower responses were observed compared to responses obtained for a sensor with immobilized, saturated phosphatidylcholine. Lipids containing -branched acyl chains, however, showed good affinity for organic vapors, and sensor responses improved 4–5-fold. Moreover, these sensors were shown to have sensitivity of the same order as the humans' sense of smell (10−5–10−6 w/w in liquid paraffin) when measured using standard odorants (isovaleric acid, skatole, etc.) for an olfactometry established in Japan. 相似文献
53.
Minoru Yamaji Ai Suzuki Fuyuki Ito Shozo Tero-Kubota Seiji Tobita Bronislaw Marciniak 《Journal of photochemistry and photobiology. A, Chemistry》2005,170(3):253-259
Photodissociation of the carbon-X (X = Br and Cl) bonds in p-bromo- and p-chloromethylbenzophenone (BMBP and CMBP) in solution were investigated by time-resolved EPR and laser flash photolysis techniques. BMBP and CMBP were found to undergo ω-bond cleavage to yield the p-benzoylbenzyl radical (BBR) at 295 K, and the quantum yields (ΦBBR) were determined. The CIDEP signal originated from BBR formed upon decomposition of CMBP was obtained while that for BMBP was absent. By using triplet sensitization of acetone, the efficiencies (BBR) of the CX bond fission in the triplet states of BMBP and CMBP were determined. The agreement between the ΦBBR and BBR values for CMBP indicates that the CCl bond dissociation occurs only in the triplet state. In contrast to CMBP, the cleavage of the CBr bond in BMBP upon direct excitation was concluded to be the event only in the excited singlet state without triplet formation, whereas the triplet state was also reactive for ω-bond dissociation. The rate of CBr bond dissociation seemed to be greater than that of intersystem crossing from the S1 to the T1 state. Schematic energy diagrams of the excited states of BMBP and CMBP were shown, and the reaction profiles were discussed from the viewpoint of the CX bond enthalpies. 相似文献
54.
Masuda Y Itoh T Koumoto K 《Langmuir : the ACS journal of surfaces and colloids》2005,21(10):4478-4481
We developed a self-assembly process of silica particles to fabricate desired patterns of colloidal crystals having high feature edge acuity and high regularity. A micropattern of colloidal methanol prepared on a self-assembled monolayer in hexane was used as a mold for particle patterning, and slow dissolution of methanol into hexane caused shrinkage of molds to form micropatterns of close-packed SiO2 particle assemblies. This result is a step toward the realization ofnano/micro periodic structures for next-generation photonic devices by a self-assembly process. 相似文献
55.
Both the enantiomers of 2,3-dihydro-2-isopropyl-2,5-dimethylfuran were synthesized employing the Sharpless asymmetric epoxidation reaction. The (R)-(—)-enantiomer of this cyclic enol ether was also synthesized starting from (R)-(—)-linalool. 相似文献
56.
Kamiya S Minamikawa H Jung JH Yang B Masuda M Shimizu T 《Langmuir : the ACS journal of surfaces and colloids》2005,21(2):743-750
A series of glucopyranosylamide lipids, N-(X-octadecenoyl)-beta-D-glucopyranosylamine [X = 13-cis (1), 11-cis (2), 9-cis (3), 6-cis (4), and 9-cis,12-cis (5)] and their saturated homologue N-octadecanoyl-beta-d-glucopyranosylamine (6), which differ in the position of a cis double bond in the C18 hydrocarbon chains, have been synthesized. The effect of the cis double bond position on the chiral self-assembly of each glycolipid has been examined by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, UV, and circular dichroism (CD). The 11-cis derivative 2 was observed to self-assemble in water to form a uniform hollow cylinder structure with about 200-nm outer diameters in >98% yields. The obtained nanotubes from 2 showed the narrowest distribution of outer diameters and also gave a negative CD band around 234-236 nm, showing the largest CD intensity among the glycolipids investigated. Thus, we found that the position of a cis double bond significantly influences the homogeneity of the outer diameters as well as growth behavior of the self-assembled nanotube structures. Chiral molecular packing driven by a possible bending structure of the unsaturated glycolipids is playing a critical role in determining tubular morphology through molecular self-assembly. 相似文献
57.
K. Terada T. Masuda Y. Yoshihashi E. Yonemochi 《Journal of Thermal Analysis and Calorimetry》2006,85(3):675-680
Isothermal
microcalorimetry was used to evaluate excipient compatibility of solid dosage
form. Oxybutynin hydrochloride and cefaclor were used as model drugs for compatibility
test with excipients. The calorimetric data for compatibility test were compared
with those of HPLC data. Evaluation of compatibility between drug and excipient
of solid dosage form might be possible to use isothermal microcalorimetry
instead of conventional method. By using microcalorimetric method, the evaluation
of the compatibility between drug and excipient could be successfully performed
with a simple operation in a short time. The application of the isothermal
microcalorimetry would be useful for the screening test of the drug compatibility
with excipients. 相似文献
58.
(Ss)-3-(p-Tolylsufinyl)-2-furaldimine was synthesized, and condensation of the chiral furaldimine with lithium ester enolates has been examined. The product distribution of the reaction is dependent upon reaction conditions and on the kind of the substituent placed on the esters. Disubstituted ester enolate resulted in the exclusive formation of (4R)-beta-lactam, while unsubstituted, tert-butyl ester enolate preferentially gave (3R)-beta-amino ester. With the monosubstituted ester enolates, the condensation afforded (4R)-beta-lactams and/or (3R)-beta-amino esters as major products. This method has been applied to an efficient route to chiral furyl beta-lactams. 相似文献
59.
Yoshio Masuda 《Thermochimica Acta》1980,39(3):235-241
The thermal dehydration reactions of two kinds of copper(II) formate dihydrate, which differ in origin and preparation history, have been investigated by means of TG, DTA and DSC. The kinetics of isothermal dehydration were studied by weight loss, and the difference in kinetic behavior between these two samples was related to the difference in origin and preparation history. On the whole, the dehydration mechanisms of these two samples were found to be phase boundary controlled contracting interface reactions. 相似文献
60.
Yoshio Masuda 《Thermochimica Acta》1983,60(2):203-210
The thermal dehydration of some rare earth metal formate dihydrates were studied by means of thermogravimetry, differential thermal analysis and differential scanning calorimetry.The dehydration took place successively as a one step reaction for all of the formate dihydrates examined. The reaction order of dehydration was found to be for all of the salts examined, which indicated that the rate of dehydration was controlled by a chemical process at a phase boundary.The values of the activation energy, frequency factor and the enthalpy change of dehydration for all of the dihydrates were 108–142 kJ mole?1, 1016–1017 min?1 and 109–147 kJ mole?1, respectively.Both the temperature at which the dehydration occurred and the enthalpy change increased as the reciprocal of the radius of the metallic ion increased. 相似文献