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31.
Atsunori Matsuda Tatsuo Matoda Toshihiro Kogure Kiyoharu Tadanaga Tsutomu Minami Masahiro Tatsumisago 《Journal of Sol-Gel Science and Technology》2004,31(1-3):229-233
Titania nanosheet-precipitated coatings have been prepared by treating SiO2-TiO2 gel films on glass substrates with hot water at 90°C under vibration. Longitudinal vibrations at about 6 Hz during the treatment enhanced the formation of titania nanosheet. The titania nanosheet consisted of several layers with a spacing of about 0.6 nm and was identified as hydrated titania with a lepidocrocite-type structure. The morphology of the titania nanosheet-precipitated coatings is probably achieved by lowering of the concentration of hydrolyzed titania species at the surface due to rapid water flow driven by the vibrations. The coatings were transparent in the visible range and showed high photocatalytic activity and antifogging property. 相似文献
32.
Ken-Ichi Ito Masamichi Nishimura Minoru Sashio Masahiro Tsunooka 《Journal of polymer science. Part A, Polymer chemistry》1994,32(11):2177-2185
It was found that amines were formed efficiently by the photolysis of O-acyloximes followed by hydrolysis in polystyrene films and the relationship between structures of O-acyloximes and yields of amines were investigated. O-phenylacetyl acetophenone oxime (PaApO), O-pivaloyl acetophenone oxime (PApO), and O-benzoyl acetophenone oxime (BApO) as monofunctional O-acyloximes and O,O′-succinyl diacetophenone oxime (SDApO) and O,O′-glutaryl diacetophenone oxime (GDApO) as bifunctional O-acyloximes were examined. The yields of amines for PaApO and SDApO under N2 were ca. 70%, which was the highest among O-acyloximes examined in this experiment. On the other hand, the yields for PApO, BApO, and GDApO were less than 15% and it was verified that the hydrogen abstraction by imino radicals via 6-membered cyclic intermediates resulted in the lowering of yields. Although the effect of oxygen under photolysis on the yields of amine for PaApO was negligible under 50% conversion of PaApO, the yield decreased with further increase in the conversion and was 50% at 90% conversion. © 1994 John Wiley & Sons, Inc. 相似文献
33.
Ichinose H Michizoe J Maruyama T Kamiya N Goto M 《Langmuir : the ACS journal of surfaces and colloids》2004,20(13):5564-5568
Enzyme-based electron-transfer reactions involved in the cytochrome P450 monooxygenase system were investigated in nanostructural reverse micelles. A bacterial flavoprotein, putidaredoxin reductase (PdR), was activated and shown to be capable of catalyzing the electron transport from NADH to electron-carrier proteins such as cytochrome b5 (tCyt-b5) and putidaredoxin (Pdx) in reverse micelles. Ferric tCyt-b5 in reverse micelles was effectively converted to its ferrous form by the exogenous addition of separately prepared reverse micellar solution harboring PdR and NADH. The fact that direct interactions of macromolecular proteins should be possible in the reverse micellar system encouraged us to functionalize a multicomponent monooxygenase system composed of the bacterial cytochrome P450cam (P450cam), putidaredoxin (Pdx), and PdR in reverse micelles. The successful camphor hydroxylation reaction catalyzed by P450cam was significantly dependent on the coexistence of Pdx, PdR, and NADH but not H2O2, suggesting that the oxygen-transfer reactions proceeded via a "monooxygenation" mechanism. This is the first report of a multicomponent cytochrome P450 system exhibiting enzymatic activity in organic media. 相似文献
34.
Polycrystalline Fe2TiO5 films were prepared on nesa silica glass substrates by the sol-gel method, and their photoanodic properties were measured in a three-electrode wet cell with an aqueous buffer solution of pH = 7. Gel films were crystallized into Fe2TiO5 when fired at 500°C. The photoanodic current significantly increased when the films were fired at 700°C, and then decreased with increasing firing temperature. Thicker films obtained by repeating the gel film deposition and firing showed smaller photocurrent, and the 50 nm thick film prepared via non-repetitive deposition exhibited the maximum photocurrent. Although the photoresponse was extended to wavelengths near 500 nm, the maximum quantum yield was as low as 0.12 at a wavelength of 340 nm. 相似文献
35.
Ooi Y Hobara D Yamamoto M Kakiuchi T 《Langmuir : the ACS journal of surfaces and colloids》2005,21(24):11185-11189
In formation of binary self-assembled monolayers (SAMs) composed of 2-aminoethanethiol (AET) and 2-mercaptoethane sulfonic acid (MES) by adsorption from an ethanol solution on Au(111), the adsorption shows nearly ideal nonideality in that the surface ratio of MES to AET in the SAM is unity and does not depend on the mixing ratio of MES to AET in the bathing ethanol solution used for preparing SAMs, chi(soln)MES, over the wide range of chi(soln)MES between 0.01 and 0.95. X-ray photoelectron spectroscopy confirms that at least 80% of AET molecules adsorbed are protonated in this range of chi(soln)MES, indicating that the electrostatic interaction between positively charged AET and negatively charged MES is responsible to the observed nonideality. Correspondingly, there appears only one cathodic peak in a linear-sweep voltammogram of the reductive desorption of the SAM, having a narrow full width at half-maximum of about 20 mV. This suggests the presence of strong lateral attractive interaction between the adsorbed thiolates. 相似文献
36.
Masahiro Irie Senzo Sasaoka Yukio Yamamoto Koichiro Hayashi 《Journal of polymer science. Part A, Polymer chemistry》1979,17(3):815-820
Photopolymerization of cyclohexene oxide in the presence of electron acceptors was studied in a bulk system (in liquid as well as in solid states). The polymerization was proved to proceed by a cationic mechanism in both states by the effect of inhibitors. In a liquid phase the light intensity dependence of the rate of polymerization and the molecular weight distribution showed a contribution of a free ionic polymerization. Any discontinuous phenomenon in the rate as well as in the molecular weight was not discerned between liquid(above ?36°C) and plastic crystal (between ?36 and ?81°C) phases. A quantum yield of monomer consumption as high as 8 × 103 was observed in the plastic crystal phase. Below ?81°C in the normal crystal phase the rate as well as the molecular weight was remarkably suppressed. 相似文献
37.
An enantiospecific coupling of propargylic esters and carbonates with arylboronic acids has been developed using a palladium catalyst. Optically active 1,3-disubstituted allenes were synthesized with high enantiomeric excesses by carrying out the reactions under basic aqueous conditions. 相似文献
38.
The reaction of cyclobutanone with an alkyne in the presence of a nickel(0) catalyst formally achieves intermolecular alkyne insertion between the carbonyl carbon and the α-carbon of a cyclobutanone, providing a six-membered carbocyclic skeleton. 相似文献
39.
Hossain MJ Yamasaki M Mikuriya M Kuribayashi A Sakiyama H 《Inorganic chemistry》2002,41(15):4058-4062
A new end-off type acyclic ligand with four hydroxyethyl arms, 2,6-bis[bis(2-hydroxyethyl)aminomethyl]-4-methylphenol [H(bhmp)], formed dinuclear cobalt(II) complexes [Co(2)(bhmp)(OAc)(2)]BPh(4) (1) and [Co(2)(bhmp)(OBz)(2)]BPh(4) (2). The complex 1.2.5CH(3)CN (C(50)H(62.5)BCo(2)N(4.5)O(9)) crystallizes in the monoclinic space group C2/c with dimensions a = 25.424(5) A, b = 13.376(2) A, c = 29.913(6) A, beta = 105.930(3) degrees, and V = 9781(3) A(3) and with Z = 8. X-ray diffraction analysis revealed a mu-phenoxo-bis(mu-acetato)dicobalt(II) core structure containing two octahedral cobalt(II) ions. Electronic spectra were investigated for 1 and 2 in the range 400-1800 nm, and the data were typical for the octahedral high-spin cobalt(II) complexes. Magnetic susceptibility was measured for 1 and 2 over the temperature range 4.5-300 K, and the data were analyzed well using our theoretical method. The best fitting parameters were kappa = 0.77, lambda = -116 cm(-1), Delta = 572 cm(-1), and J = -0.44 cm(-1) for complex 1 and kappa = 0.96, lambda = -93 cm(-1), Delta = 616 cm(-1), and J = -0.33 cm(-1) for complex 2. 相似文献
40.