著者
Takaaki Ikuno Atsuro Nomura Kenta Iyoki Ayae Sugawara-Narutaki Tatsuya Okubo Atsushi Shimojima
出版者
(社)日本化学会
雑誌
Chemistry Letters (ISSN:03667022)
巻号頁・発行日
vol.42, no.3, pp.316-317, 2013-03-05 (Released:2013-03-02)
参考文献数
14
被引用文献数
10

A facile approach is demonstrated for the preparation of hollow mesoporous silica nanoparticles with large pore volume and high dispersibility. Core–shell nanoparticles consisting of iron oxide (α-Fe2O3) core and mesostructured silica–surfactant composite shell are treated with hexamethyldisiloxane under acidic conditions to achieve capping of silanol groups and removal of both surfactants and the Fe2O3 cores in a single step.
著者
Tomoyuki Iwamoto Yoichi Masui Jiacheng Wang Makoto Onaka
出版者
(社)日本化学会
雑誌
Chemistry Letters (ISSN:03667022)
巻号頁・発行日
vol.42, no.3, pp.247-249, 2013-03-05 (Released:2013-02-23)
参考文献数
12
被引用文献数
4

A novel template-free and postsynthetic preparation of a highly porous carbon nitride material, nanoC3N4, was developed using concentrated sulfuric acid as the dispersion medium, followed by impregnation with ethanol. nanoC3N4 has a structure similar to that of graphitic carbon nitride composed of melem polymers but has a stronger basicity.
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
Satoshi Ueno Ryohei Maeda Shohei Yasuoka Ryoichi Kuwano
出版者
(社)日本化学会
雑誌
Chemistry Letters (ISSN:03667022)
巻号頁・発行日
vol.42, no.1, pp.40-42, 2013-01-05 (Released:2012-12-22)
参考文献数
59
被引用文献数
9 2

Amination at the β-position of 2-arylpropionitriles through catalytic dehydrogenation occurred by using [PdCl2(PMe3)2] catalyst and bromobenzene. This is the first catalytic reaction involving the direct dehydrogenation of saturated nitriles.
著者
Shoko Suzuki Ryota Sakamoto Hiroshi Nishihara
出版者
(社)日本化学会
雑誌
Chemistry Letters (ISSN:03667022)
巻号頁・発行日
vol.42, no.1, pp.17-18, 2013-01-05 (Released:2012-12-22)
参考文献数
23
被引用文献数
3

[Ru(tpy)(picSO)]BF4 (tpy: 2,2′:6′,2′′-terpyridine, picSO: 6-[(methylsulfinyl)methyl]picolinate) undergoes profound linkage isomerization behavior between stable S-bound and metastable O-bound isomers. S-[RuII(tpy)(picSO)]BF4 experiences photoisomerization to O-[RuII(tpy)(picSO)]BF4 upon irradiation with 436 nm light, whereas the back reaction is triggered with 546 nm light. Electrochemical linkage isomerization also takes place.
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
Teruaki Mukaiyama Shu Kobayashi Hiromi Uchiro Isamu Shiina
出版者
(社)日本化学会
雑誌
Chemistry Letters (ISSN:03667022)
巻号頁・発行日
vol.19, no.1, pp.129-132, 1990 (Released:2006-05-08)
被引用文献数
31 83 76

Highly enantioselective aldol reaction of silyl enol ethers with aldehydes is performed by the use of a catalytic amount of chiral diamine coordinated tin(II) triflate according to a slow addition procedure.
著者
Youhei Takeda Junpei Hayakawa Kazuki Yano Satoshi Minakata
出版者
(社)日本化学会
雑誌
Chemistry Letters (ISSN:03667022)
巻号頁・発行日
vol.41, no.12, pp.1672-1674, 2012-12-05 (Released:2012-12-08)
参考文献数
37
被引用文献数
3

An intermolecular benzylic C–H bond amination utilizing the combination of chloramine-T and I2 without the aid of transition-metal catalysts has been developed. The reaction was found applicable to a variety of benzene-substituted alkanes, as well as to an adamantane derivative to give N-alkylated p-tosylamides in good yields.
著者
Hisatoshi Konishi Hidekazu Nakamaru Hideki Nakatani Tsuyoshi Ueyama Kazuhiro Kobayashi Osamu Morikawa
出版者
(社)日本化学会
雑誌
Chemistry Letters (ISSN:03667022)
巻号頁・発行日
vol.26, no.2, pp.185-186, 1997 (Released:2004-05-01)
参考文献数
12
被引用文献数
11 6

The partial bromination of calix[4]resorcinarene with a limited amount of N-bromosuccinimide was examined. The ratio of the two dibromo derivatives, distal- and proximal-isomers, was 10:1, which is much different from the statistical value of 1:2. The simple procedure for the preparation of the distal-dibromo derivative is described.
著者
Mengsu Yang Richard Y. C. Kong Najam Kazmi Andrew K. C. Leung
出版者
(社)日本化学会
雑誌
Chemistry Letters (ISSN:03667022)
巻号頁・発行日
vol.27, no.3, pp.257-258, 1998 (Released:2003-02-28)
参考文献数
10
被引用文献数
18

Glass slides and silicon chips were modified with aminosilane and various linker molecules to provide activated surfaces for covalent immobilization of oligonucleotides under ambient condition, and the surface-attached oligonucleotides remain active for solid-phase DNA hybridization and polymerase chain reaction.
著者
Yasuhiro Morisaki Yoshiki Chujo
出版者
(社)日本化学会
雑誌
Chemistry Letters (ISSN:03667022)
巻号頁・発行日
vol.41, no.9, pp.840-846, 2012-09-05 (Released:2012-08-25)
参考文献数
67
被引用文献数
27 5

Incorporation of a [2.2]paracyclophane skeleton into a conjugated polymer main chain affords a polymer comprising stacked π-electron systems. In this article, we describe the synthesis and optical properties of some [2.2]paracyclophane-based polymers on the basis of the results of our resent research. We discuss the role of [2.2]paracyclophane in the polymer backbone, through-space conjugation of the polymer, and the feasibility of using the titled polymers as single molecular wires that allow for unidirectional energy and charge transfer via through-space interactions.
著者
Tomoya Tanaka Hiroyuki Mayama Yoshimune Nonomura
出版者
(社)日本化学会
雑誌
Chemistry Letters (ISSN:03667022)
巻号頁・発行日
vol.41, no.9, pp.960-961, 2012-09-05 (Released:2012-09-01)
参考文献数
14

We successfully determined the three-dimensional structure of agar gel droplets on multipillared surfaces. The contact angle, length of penetration of the agar gel into the interspace between pillars, and curvature of the bottom surface of the droplets were changed with respect to changes in the volume and concentration of the aqueous agar solution and the distance between the surface-bound pillars.
著者
Yoshimune Nonomura Tomoya Tanaka
出版者
(社)日本化学会
雑誌
Chemistry Letters (ISSN:03667022)
巻号頁・発行日
vol.41, no.9, pp.952-953, 2012-09-05 (Released:2012-09-01)
参考文献数
19

We observed the condensation of water and ethanol on a hydrophobic polymer film coated with fluorinated silicone particles and identified five states: the circular droplet, ellipsoidal droplet, network, huge droplet, and film states. The shape of the condensed droplets changed with the particle density and the wettability of the particles by the liquid.
著者
Atsuhiro Osuka Hitomi Suzuki Kazuhiro Maruyama
出版者
(社)日本化学会
雑誌
Chemistry Letters (ISSN:03667022)
巻号頁・発行日
vol.11, no.5, pp.653-656, 1982-05-05 (Released:2006-03-27)
参考文献数
12
被引用文献数
1

Photolysis of the title compounds in benzene gave spirophthalides and E- and Z-alkylidene phthalides via preferential α-cleavage at the more crowded side. On the basis of quantum yields and triplet lifetimes, this preference is indicated to arise from the different efficiencies of the radical recombination of possible biradicals.
著者
Kazuhiro Maruyama Atsuhiro Osuka Katsuhiko Nakagawa Kenzo Tabuchi Hirohito Shimizu Hitomi Suzuki
出版者
(社)日本化学会
雑誌
Chemistry Letters (ISSN:03667022)
巻号頁・発行日
vol.15, no.11, pp.1849-1852, 1986-11-05 (Released:2006-03-27)
参考文献数
7
被引用文献数
1

Irradiation of 2-substituted 4-alkylidene-2,3-epoxy-1-tetralone results in the rearrangement to 3-(2-oxoalkylidene)-1-indanone or the E-Z isomerization around the double bond. These photoreactions are suggested to occur from the (π,π*) triplet excited state.
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
Joe Otsuki Koichi Narutaki Jan M. Bakke
出版者
(社)日本化学会
雑誌
Chemistry Letters (ISSN:03667022)
巻号頁・発行日
vol.33, no.3, pp.356-357, 2004 (Released:2004-02-23)
参考文献数
16
被引用文献数
26

Modulation of luminescence intensity triggered by light input is demonstrated. The system consists of a Zn–porphyrin and an azopyridine derivative, which axially coordinates to Zn–porphyrin and quenches its fluorescence more efficiently in the trans-form than in the cis-form. Thus, light-induced isomerization of the azopyridine results in the increase/decrease of the porphyrin fluorescence.
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.
著者
Ryohei Yamakado Shinri Sugimoto Shin-ichi Matsuoka Masato Suzuki Yasuhiro Funahashi Koji Takagi
出版者
(社)日本化学会
雑誌
Chemistry Letters (ISSN:03667022)
巻号頁・発行日
vol.41, no.3, pp.249-251, 2012-03-05 (Released:2012-02-25)
参考文献数
18
被引用文献数
9

m-Calix[3]amide having pyridine on the benzene ring (PyC3A) was synthesized by the cyclization of methyl 3-nonylamino-5-(pyridin-4-yl)benzoate using lithium 1,1,1,3,3,3-hexamethyldisilazide (LiHMDS). The molecular cage 3Pd·2PyC3A was prepared from a 2:3 mixture of PyC3A and [Pd(dppp)(OTf)2] in CDCl3/CD3OD (5/1 in volume). On the other hand, in CDCl3, the formation of a polymeric mixture was confirmed.