著者
Yoshihiro Nemoto Takayuki Hirai
出版者
(社)日本化学会
雑誌
Bulletin of the Chemical Society of Japan (ISSN:00092673)
巻号頁・発行日
vol.77, no.5, pp.1033-1036, 2004 (Released:2004-05-06)
参考文献数
13

A photocatalyst can be used for various applications. Such materials are semiconductors which are stable to photoirradiation, for example, TiO2. Most of these materials require UV light. There are many kinds of semiconductors which are unstable to photoirradiation, but which have a visible light response. In this study, it is shown that a thin Au film or Au nano particles on the surface of the photocatalyst reduced the photodecomposition of the photocatalyst. Although the surfaces of the samples were completely covered by Au, photocatalytic activity was observed in all the Au-coated samples. The Au-coating on the surface enhances the photocatalysis of a coated photocatalyst.
著者
Tomohiro Iwai Masaya Sawamura
出版者
(社)日本化学会
雑誌
Bulletin of the Chemical Society of Japan (ISSN:00092673)
巻号頁・発行日
vol.87, no.11, pp.1147-1160, 2014-11-15 (Released:2014-11-15)
参考文献数
107
被引用文献数
12

Triethynylphosphines with bulky end caps such as triarylsilyl and triarylmethyl groups at alkyne termini have a novel molecular shape presenting a large, deep metal-binding cavity. The hollow-shaped triethynylphosphines functioned as effective ligands in the rhodium-catalyzed hydrosilylation of ketones with triorganosilanes due to the preferential formation of a mono-P-ligated rhodium species. Furthermore, the phosphines displayed remarkable rate enhancement in the gold(I)-catalyzed alkyne cyclization constructing six- to eight-membered ring compounds. It is proposed that the cavity in the ligand forces a nucleophilic center of the acetylenic compounds close to the gold-bound alkyne, making ring-closing anti attack feasible.
著者
Youichi Ohara Kenkichi Tanaka Takahiro Hayashi Haruo Tomita Shigeru Motani
出版者
(社)日本化学会
雑誌
Bulletin of the Chemical Society of Japan (ISSN:00092673)
巻号頁・発行日
vol.77, no.4, pp.599-605, 2004 (Released:2004-04-02)
参考文献数
12
被引用文献数
16 6

This technology is concerned with a new type of extruded polystyrene foam (XPS), which gives high performance of thermal insulation without containing any fluorocarbons as a blowing agent. Avoiding such typically harmful materials will help solve global environmental problems like ozone layer depletion and global warming. Kaneka Corporation developed this technology for the first time in the world. As a blowing agent of this new XPS in place of fluorocarbons we adopted isobutane, an excellent green gas that helps prevent ozone layer depletion and global warming. However, there is a problem: it is difficult to secure high performance of thermal insulation and flame retardation when isobutane is used. This originates from the fact that isobutane has a higher thermal conductivity than fluorocarbons, and is highly flammable. To overcome the former problem, we found a novel cell structure to secure high performance of thermal insulation, and we developed new technologies to control it. To solve the latter problem, namely securing flame retardation, we clarified the mechanism to suppress combustion of isobutane, and developed a new flame retardation technology by the addition of specific compounds. As a result of a combination of these technologies, we were able to develop and commercialize a new XPS with high performance of thermal insulation. These technologies directly contribute to prevent adverse effects on the global environment such as ozone layer depletion and global warming, by not using fluorocarbons. And, in addition, these technologies indirectly but more greatly contribute to global warming prevention by the reduction in carbon dioxide emissions through a high effect of energy conservation as a thermal insulator. Therefore, the thermal insulator with these technologies is valuable for environmental protection. And as the needs for a material for better energy conservation will increase, the contribution of this technology will expand much more in the future.
著者
Takuya Okamoto Takeshi Ishikawa Yoshiyuki Koyano Norifumi Yamamoto Kazuo Kuwata Masataka Nagaoka
出版者
(社)日本化学会
雑誌
Bulletin of the Chemical Society of Japan (ISSN:00092673)
巻号頁・発行日
vol.86, no.2, pp.210-222, 2013-02-15 (Released:2013-02-15)
参考文献数
95
被引用文献数
20 4

For the purpose of providing a realistic description of the reaction mechanisms in large molecular systems, we propose a quantum mechanical/molecular mechanical (QM/MM) method combined with the ab initio fragment molecular orbital (FMO) method, i.e., the ab initio FMO-QM/MM method. By connecting a molecular dynamics (MD) program AMBER with an FMO program PAICS, we have implemented an AMBER-PAICS interface (AP-IF). Using the AP-IF, we demonstrate three example applications: (a) a hydrogen fluoride and water molecular clusters, (b) an alanine dipeptide in aqueous solution, and (c) a prion protein–GN8 complex. From these results, it is confirmed that the FMO-QM/MM method offers a good compromise between chemical accuracy and computational cost and enables us to obtain in ab initio quality the inter- and intramolecular interaction energies between molecules or residues in large molecular systems such as solution and biomolecule, by using the dynamics-based interfragment interaction energy (IFIE) analysis.
著者
Toshiyuki Itoh Hitomi Inoue Sachie Emoto
出版者
The Chemical Society of Japan
雑誌
Bulletin of the Chemical Society of Japan (ISSN:00092673)
巻号頁・発行日
vol.73, no.2, pp.409-416, 2000 (Released:2001-10-31)
参考文献数
56
被引用文献数
14

Synthesis of (1S,2R)-1-[(E)-hex-1-en-1-yl]-2-vinylcyclopropane (dictyopterene A), which was isolated from the essential oil of algae of the genus Dictyopteris in Hawaii, has been demonstrated using optically active tributylstannylcyclopropane as a starting chiral synthon.
著者
Tatsuya Yamamoto Shoji Shinamura Eigo Miyazaki Kazuo Takimiya
出版者
(社)日本化学会
雑誌
Bulletin of the Chemical Society of Japan (ISSN:00092673)
巻号頁・発行日
vol.83, no.2, pp.120-130, 2010-02-15 (Released:2010-02-15)
参考文献数
40
被引用文献数
59

In order to gain an insight into the relationship between the molecular structure and the semiconductor characteristics of highly π-extended heteroarene-based organic semiconductors, three structural isomers of dinaphthothieno[3,2-b]thiophenes with C2h symmetry were investigated. Of these, two isomers, dinaphtho[2,1-b:2′,1′-f ]thieno[3,2-b]thiophene (2) and dinaphtho[1,2-b:1′,2′-f ]thieno[3,2-b]thiophene (3), were newly synthesized, characterized, and utilized as active semiconducting layers in organic field-effect transistors (FETs). Detailed investigation of the physicochemical properties of 2 and 3, together with another isomer, dinaphtho[2,3-b:2′,3′-f ]thieno[3,2-b]thiophene (1), indicated that the electronic structures of the three isomers are fairly different from each other despite having the same molecular formula and the same aromatic constituents. Comparison of the molecular arrangements in the crystals elucidated by X-ray structural analysis implied that the molecular shape and the thus-induced favorable intermolecular interactions play important roles in determining the entire molecular arrangement. The characteristics of 2- and 3-based FETs with maximum field-effect mobilities (μFET s) of 10−3–10−2 cm2 V−1 s−1 were inferior to those of 1-based FETs with μFET s up to 3.0 cm2 V−1 s−1. The inferior characteristics of 2- and 3-based devices were due to film morphology as elucidated by atomic force microscopy (AFM) and supported by theoretical calculations of electronic structure in the solid state. Together, the results indicate that the molecular structure and shape, even for similar heteroarenes with the same molecular formula and symmetry, are important parameters to determine the solid-state properties of organic semiconductors.
著者
Yoichiro Kuninobu Kazuhiko Takai
出版者
(社)日本化学会
雑誌
Bulletin of the Chemical Society of Japan (ISSN:00092673)
巻号頁・発行日
vol.85, no.6, pp.656-671, 2012-06-15 (Released:2012-06-15)
参考文献数
97
被引用文献数
31

Rhenium- or manganese-catalyzed transformations based on the cleavage of inactive bonds, such as carbon–hydrogen and carbon–carbon bonds are discussed. Such transformations are recognized as key methods to realize efficient and powerful reactions. We also reveal novel regio- and/or stereodefined cycloaddition reactions using a rhenium or manganese catalyst. Most of the catalytic activities are typical of rhenium and manganese carbonyl complexes.
著者
Marc Schröder Kyoko Nozaki Tamejiro Hiyama
出版者
(社)日本化学会
雑誌
Bulletin of the Chemical Society of Japan (ISSN:00092673)
巻号頁・発行日
vol.77, no.10, pp.1931-1932, 2004 (Released:2004-10-09)
参考文献数
17
被引用文献数
21

Treatment of phosphine–boranes with molecular sieves 4Å in a mixture of an ethereal solvent and an alcohol provided deprotected free phosphines in quantitative yields. The phosphines can be obtained by a simple filtration/crystallization procedure in most cases. It should be noted that the current method is successfully applied to the deprotection of a phosphite–borane for the first time.
著者
Harushige Fujita Masataro Yamashita
出版者
(社)日本化学会
雑誌
Bulletin of the Chemical Society of Japan (ISSN:00092673)
巻号頁・発行日
vol.46, no.11, pp.3553-3554, 1973 (Released:2006-03-27)
参考文献数
14
被引用文献数
1

The aprotic polar solvents, such as DMF (N,N-dimethylformamide) and DMSO (dimethyl sulfoxide), accelerated very effectively the methylenation of 1,2-dihydroxy-4- (I), 1,2-dihydroxy-3,4-dimethoxy-5- (II), and 1,2-dihydroxy-3-methoxy-5-allylbenzene (III) in the presence of bronze and cupric oxide as catalysts.
著者
Michiyasu Sakagami Takahiro Sasamori Heisuke Sakai Yukio Furukawa Norihiro Tokitoh
出版者
(社)日本化学会
雑誌
Bulletin of the Chemical Society of Japan (ISSN:00092673)
巻号頁・発行日
vol.86, no.10, pp.1132-1143, 2013-10-15 (Released:2013-10-15)
参考文献数
62
被引用文献数
27

1,2-Bis(ferrocenyl)dipnictenes bearing a Pn=Pn π-spacer (Pn: P (1), Sb (2), and Bi (3)) between two ferrocenyl units have been synthesized as stable compounds. Not only their molecular structures and fundamental properties but also their redox behavior have been systematically disclosed. Interestingly, in the reduction region, the dipnictenes showed two pseudo-reversible one-electron redox couples at low temperature, suggesting possible generation of the corresponding radical anion and dianion species. On the other hand, they showed three-step one-electron oxidation processes in the oxidation region. The first two oxidation steps would correspond to those of the two ferrocenyl moieties, while the third step would be that of the Pn=Pn π-spacer moiety, respectively. Thus, these 1,2-bis(ferrocenyl)dipnictenes with a Pn=Pn π-spacer should be stable multiredox systems reflecting unique properties of a double bond between heavier 15 group elements. As a result, all Pn=Pn units (Pn: P, Sb, and Bi) were found to work as a more effective π-spacer than those of 2nd row elements such as C=C and N=N.
著者
Taku Shoji Akifumi Maruyama Mitsuhisa Maruyama Shunji Ito Tetsuo Okujima Junya Higashi Kozo Toyota Noboru Morita
出版者
(社)日本化学会
雑誌
Bulletin of the Chemical Society of Japan (ISSN:00092673)
巻号頁・発行日
pp.20130275, (Released:2013-11-08)
被引用文献数
15

6-Methoxy- and 6-dimethylaminoazulenes with methylthio groups at the 1- or 1,3-positions have been prepared by electrophilic substitution of the corresponding azulenes with DMSO in the presence of acid anhydride, followed by treatment with Et3N. The products, 1-methylthioazulenes, reacted with Tf2O to afford the corresponding 1,1’-biazulene derivatives in moderate yields. The redox behavior of these azulene and 1,1’-biazulene derivatives was examined by cyclic voltammetry (CV), which revealed reversible electron transfers under electrochemical oxidation conditions. 6-Dimethylamino-1,3-bis(methylthio)azulenes with a heteroaryl group at the 2-position were also prepared by the reaction of 6-dimethylamino-1,3-bis(methylthio)azulene with triflates of N-containing heterocycles, i.e., pyridine, quinoline, isoquinoline, acridine, and 1,10-phenanthroline, followed by treatment with KOH in alcohols.
著者
Dong-Heon Lee Narasimha N. Murthy Kenneth D. Karlin
出版者
(社)日本化学会
雑誌
Bulletin of the Chemical Society of Japan (ISSN:00092673)
巻号頁・発行日
vol.80, no.4, pp.732-742, 2007-04-15 (Released:2007-04-13)
参考文献数
80
被引用文献数
6

Copper(I)–dioxygen reactivity studies utilizing new binucleating ligands are described. When catalytic quantities of either CuI or CuII salts were introduced to LH2, which is a dinucleating ligand with two tridentate donors connected via a methylene group at a bis(2-pyridyl)methane junction, dioxygen addition caused complete oxygenation to give bis(2-pyridyl)ketone product L=O. Isolated dicopper(I) complex [CuI2(LH2)]2+ (1) also reacted with excess O2 to give L=O. Additional observations were consistent with a mechanism that does not involve “oxygen-activation” in this process. Ketone hydration and gem-diol(ate) copper(II)-coordination occurred by addition of copper(II)–perchlorate to L=O, giving [CuII2{L(OH)(O−)}Cu2II(−OClO3)]2+ (4), with a bridging alkoxide moiety (X-ray). Oxygenation of [CuI2(L=O)(CH3CN)2]2+ (2) (2/O2 = 0.5, i.e., Cu/O2 = 4:1 manometry), gave [CuII2{L(O−)2}(−OClO3)]+ (5), where both oxygen atoms of the doubly deprotonated gem-diolate bind separate copper(II) ions; mass spectrometric data showed that one of the two oxygen atoms of the gem-diolate L(O−)2 came from O2. An oxo–dicopper(II) species is suggested as an important intermediate, which is supported by the observation that reaction of 2 with NO or iodosylbenzene also produced 5 in high yields. Complexes 4 and 5 are acid–base conjugate pairs and can be readily interconverted using Et3N or HClO4(aq) reagents.
著者
Kentaro Okuma Koki Hirano Chisato Shioga Noriyoshi Nagahora Kosei Shioji
出版者
(社)日本化学会
雑誌
Bulletin of the Chemical Society of Japan (ISSN:00092673)
巻号頁・発行日
vol.86, no.5, pp.615-619, 2013-05-15 (Released:2013-05-15)
参考文献数
30
被引用文献数
19

By combination of 1,3-dipolar cycloaddition and N–O single bond insertion, tandem synthesis of dibenzo[1,4]oxazepino[4,5-a]quinolines was accomplished. Reaction of quinoline N-oxides with arynes afforded 2-(2-hydroxyphenyl)quinolines and 7-membered pentacyclic oxazepino[4,5-a]quinolines.
著者
Takanori Shibata Kyoko Takami Yoshikazu Arai Kyoji Tsuchikama Shunsuke Maekawa
出版者
(社)日本化学会
雑誌
Bulletin of the Chemical Society of Japan (ISSN:00092673)
巻号頁・発行日
vol.77, no.10, pp.1937-1938, 2004 (Released:2004-10-09)
被引用文献数
1

Lithium butatrienolates were prepared in situ by the 1,4-elimination from 2-butynyl trimethylsilyl ethers along with a retro-Brook rearrangement. The addition reaction of the enolates with the aldehydes afforded β-hydroxy-α-vinylidene acylsilanes.
著者
Jin Ishii Masayuki Toyoshima Miyuki Chikae Yuzuru Takamura Yoshiko Miura
出版者
The Chemical Society of Japan
雑誌
Bulletin of the Chemical Society of Japan (ISSN:00092673)
巻号頁・発行日
vol.84, no.5, pp.466-470, 2011-05-15 (Released:2011-05-15)
参考文献数
20
被引用文献数
22

A novel recognition element has been synthesized using glycopolymer-modified gold nanoparticles (GNPs) in sugar ratios of 0, 6, 12, and 50%. The as-synthesized glycopolymer-modified GNPs have been employed in a novel lateral flow assay for the detection of proteins. A test solution of concanavalin A (ConA) at 0.01–100 µg mL−1 was readily detectable with the glycopolymer-modified GNPs with a sugar ratio of 6%. The results were clear enough to be visible with the naked eye, which demonstrates the convenience of this lateral flow assay for performing the detection of Shiga toxins and influenza viruses. Therefore, this lateral flow assay provides an attractive biosensor for the detection of proteins without the handling of toxic reagents, while allowing an easy and rapid procedure.
著者
Juzo Oyamada Mariko Sakai Yasunori Yamada Tsugio Kitamura
出版者
(社)日本化学会
雑誌
Bulletin of the Chemical Society of Japan (ISSN:00092673)
巻号頁・発行日
vol.86, no.1, pp.129-137, 2013-01-15 (Released:2013-01-15)
参考文献数
44
被引用文献数
8 1

The reaction of mesitylene with ethyl propiolate in the presence of [Pd(dppe)(OAc)2] in TFA at 30 °C for 5 h gave diethyl (2E,4Z)-4-[(2,4,6-trimethylphenyl)methylene]-2-pentenedioate selectively. Screening several bidentate phosphines ligands showed that dppe and dppm ligands are good for the arylbutadiene formation. This reaction was applied to other electron-rich arenes and found to be effective for synthesis of arylbutadienes and extended π-conjugated molecules. The regio- and stereoselective addition of an arene to propiolate was confirmed by NMR and single-crystal X-ray structural analyses of the products, suggesting that the arylbutadiene formation consisted of anti addition of an arene and a metal to the triple bond of ethyl propiolate, followed by syn addition to another molecule of ethyl propiolate. Similarly, the reaction of various arenes with ethyl propiolate in the presence of [Pt(dppe)(OTf)2] catalyst gave arylbutadienes selectively. In the Pd- or Pt-catalyzed reaction of arenes with ethyl propiolate, it was found that a bidentate ligand controlled the reaction to lead the formation of arylbutadienes.
著者
Masatoshi Osawa
出版者
(社)日本化学会
雑誌
Bulletin of the Chemical Society of Japan (ISSN:00092673)
巻号頁・発行日
vol.70, no.12, pp.2861-2880, 1997 (Released:2006-06-20)
参考文献数
102
被引用文献数
588

Molecules adsorbed on evaporated thin metal films exhibit enormously strong infrared absorption. The thin metal films that exhibit the surface-enhanced infrared absorption (SEIRA) consist of metal particles much smaller than the wavelength of light. Electric field associated with the incident infrared radiation is enhanced via the excitation of localized plasmon of the particles, yielding the absorption enhancement. Preferential orientation and the change in absorption coefficient of molecules caused by chemisorption onto the metal surface provide additional enhancement. Most characteristic observations in SEIRA experiments are well explained by a simple electromagnetic theory. The infrared spectroscopy utilizing the SEIRA effect is promising as a new surface analytical tool. In particular, it is very useful for in situ studies of electrode/electrolyte interfaces. By the combined use of the attenuated-total-reflection technique, reactions and adsorption/desorption of molecules at the interfaces can be investigated at a high sensitivity without the interference from the bulk solution. The high sensitivity of this technique enables dynamic (or time-resolved) infrared monitoring of reactions and other time-dependent phenomena at the electrochemical interface at time-resolutions ranging from microseconds to milliseconds. Two-dimensional correlation analysis of time-resolved spectra highlights certain useful information that is not clearly seen in the usual one-dimensional spectra.
著者
Kazuhiro Maruyama Hiroko Yamada Atsuhiro Osuka
出版者
(社)日本化学会
雑誌
Bulletin of the Chemical Society of Japan (ISSN:00092673)
巻号頁・発行日
vol.63, no.12, pp.3462-3466, 1990 (Released:2006-06-05)
参考文献数
19
被引用文献数
5

We applied the Chemically Induced Dynamic Nuclear Polarization (CIDNP) technique to the photochemical reaction of pheophytin a (P1) and 4-methoxyphenol (1) in benzene-d6. The observed CIDNP effects were explained in terms of reversible electron-transfer reactions from 1 to 3(P1)* and from (P1)\ ewdot to (1)\underset.+. The polarized signals of P1 were induced from the in-cage recombination of the triplet radical ion pair.
著者
Hirofumi Nakamura Masahide Terazima Noboru Hirota Satoshi Nakajima Atsuhiro Osuka
出版者
(社)日本化学会
雑誌
Bulletin of the Chemical Society of Japan (ISSN:00092673)
巻号頁・発行日
vol.68, no.8, pp.2193-2202, 1995 (Released:2006-07-09)
参考文献数
37
被引用文献数
11

Charge separated ion-pair (IP) states formed from three distance-fixed photosynthetic triads were studied by the time-resolved EPR method. Upon photoexcitation of the triads in THF at 77 K, small and narrow signals were observed at the central parts of broad EPR spectra due to the excited triplet states of the chromophores. These signals were assigned to secondary, fully charge separated IP states by the simulation based on the spin-correlated radical pair mechanism. Time dependence of the TREPR signals indicates that charge separation occurs in the singlet manifold as in the case of the photoexcited state dynamics at room temperature. Estimated electron exchange interactions, J, are in the order of 10−2—10−3 mT, which is in line with the observed long lifetimes of the IP states.
著者
Yoshiaki Nakao
出版者
(社)日本化学会
雑誌
Bulletin of the Chemical Society of Japan (ISSN:00092673)
巻号頁・発行日
pp.20120081, (Released:2012-06-28)
参考文献数
166
被引用文献数
72

Addition reactions of the organic and cyano groups of nitriles through cleavage of the C–CN bonds, namely carbocyanation, have been developed using nickel/Lewis acid (LA) cooperative catalysis. Originally, the reaction was performed with a nickel catalyst alone and was limited to the use of aryl and allyl cyanides as the nitrile substrates. By employing LA cocatalysts, the rate of the arylcyanation was accelerated significantly and the scope of nitriles used in the reaction across alkynes was expanded to include alkenyl, alkynyl, and alkyl cyanides. The high chemo-, regio-, and stereoselectivities of the alkyne–carbocyanation reactions were highlighted by the syntheses of biologically active compounds including the synthetic precursor of P-3622 and plaunotol, which possess defined tri- or tetrasubstituted ethene structures. Intramolecular arylcyanation of alkenes was also achieved by cooperative catalysis. Mechanistic studies on this particular transformation allowed us to identify several reaction intermediates, which revealed the modes of the cooperative catalysis derived from nickel- and aluminum-based LA. Intramolecular arylcyanation was achieved in an enantioselective manner using optically active bidentate phosphorus ligands, affording a protocol to introduce both a quaternary stereocenter and a cyano functionality without by-product generation.