- 著者
- Riichiro Kimura Dinh Thanh Nghia Junji Wakabayashi Shanmugam Palani Elangovan Masaru Ogura Tatsuya Okubo
- 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.85, no.4, pp.527-532, 2012-04-15 (Released:2012-04-15)
- 参考文献数
- 46
- 被引用文献数
- 5
In this study, phase changes, catalytic active species that appeared at the phase change, and the corresponding water tolerance of samples obtained upon thermal treatment from K2CO3-supported microsized and nanosized sodalite as diesel-soot combustion catalyst are examined. We have shown the successful preparation of nepheline with water tolerance from sodalite as starting material. It is confirmed that the interaction between alkali metal carbonate and crystalline aluminosilicate is prerequisite for enhancing water tolerance of the catalytically active component, Na/K carbonate, located on the nepheline.
- 著者
- Masashi Hasegawa Kota Daigoku Kenro Hashimoto Hiroyuki Nishikawa Masahiko Iyoda
- 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.1, pp.51-60, 2012-01-15 (Released:2012-01-15)
- 参考文献数
- 73
- 被引用文献数
- 52
Intramolecular interactions of face-to-face tetrathiafulvalenes (TTFs) in 1,8-bis(tetrathiafulvalenyl)naphthalene frameworks were investigated in neutral and cationic states. From X-ray analysis and NMR spectroscopy on neutral 1,8-bis(tetrathiafulvalenyl)naphthalenes, which exist as a mixture of syn- and anti-isomers in solution, there is steric repulsion between TTF moieties. However, analysis of the cyclic voltammogram (CV) revealed that a strong attractive interaction was present in the cation radical state. Electronic spectra of the cation radical state showed the presence of a mixed-valence (MV) state with a strong charge resonance feature. ESR spectra of the 1,8-bis(tetrathiafulvalenyl)naphthalene cation radical showed a typical signal of an MV state. Furthermore, a π-dimer, which exhibits pronounced Davydov splitting in the electronic spectra, was formed in the dication state. The observed absorption bands in the electronic spectra were characterized by using quantum chemical calculations of the cation radical and dication species. NMR spectra of both the π-dimer and tetracation species show either a deshielding effect due to cationic charge or a shielding effect due to diamagnetic ring currents. To our knowledge, this is the first reported example of a 1H NMR spectrum of TTF π-dimer.
- 著者
- Katsuhiko Ariga Ajayan Vinu Yusuke Yamauchi Qingmin Ji Jonathan P. Hill
- 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.1, pp.1-32, 2012-01-15 (Released:2012-01-15)
- 参考文献数
- 551
- 被引用文献数
- 629
Although mesoporous materials have well-defined pore structures, these fine materials can surprisingly be produced by employing a set of conventional and simple procedures such as mixing, heating, filtration, and washing, using low-cost materials. They can be regarded as easy-to-make bulk nanostructured materials. Mesoporous materials have great potential for use in both macroscopic applications and nanotechnology. In this account, we introduce examples of recent developments in mesoporous materials involving innovations in their components and structural designs and concentrating on our own recent progress. These examples include syntheses of mesoporous silica, metal oxides, semiconductive materials, metals, alloys, organic composites, biomaterial composites, carbon, carbon nitride, and boron nitride, as innovative components. As structural innovations for mesoporous materials, various film preparations, pore alignments, and hierarchic structures are described together with their related functions including sensing and controlled release of target molecules.
- 著者
- Kin-ya Tomizaki Masaki Obi Hisakazu Mihara
- 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.85, no.1, pp.69-78, 2012-01-15 (Released:2012-01-15)
- 参考文献数
- 23
- 被引用文献数
- 2
We propose a novel, noncompetitive, label-free, and on-chip immunoassay format based on the excluded volume effect by a target antibody that is itself bound to the corresponding epitope on a biochip. The advantage of the present method is that it only requires a biotin-tethering peptide epitope (capture agent) and fluorophore-labeled-avidin (a signal-generating agent) pair for signal readout. The method is based on the interaction between a nonlabeled target antibody and the corresponding peptide epitope of the antigen decelerating the association rate of the fluorophore-labeled avidin to the biotin moiety at the end of the peptide epitope due to the excluded volume effect of the target antibody. This causes significant changes in signal intensity. Without the target antibody, there is no interference in the binding of the signal-generating agent. The use of other specific interactions would allow fine-tuning of the excluded volume and binding rate to the capture agent to improve sensitivity and versatility.
- 著者
- Hirofumi Nobukuni Takuya Kamimura Hidemitsu Uno Yuichi Shimazaki Yoshinori Naruta Fumito Tani
- 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.1111210384-1111210384, (Released:2011-11-29)
- 参考文献数
- 32
- 被引用文献数
- 13
Cyclic nickel and free-base porphyrin dimers (Ni2-CPDPy and H4-CPDPy) include fullerene C70 both in solution and in the crystals. Based on the 13C NMR spectra in solution, the included C70 molecule inside the cavity of Ni2-CPDPy shows both end-on and side-on orientations, whereas the C70 molecule within H4-CPDPy has only a side-on orientation toward the porphyrin rings. X-ray crystallography revealed both “end-on” and “side-on” orientations of C70 in the crystal structure of the inclusion complex of Ni2-CPDPy and C70. This is the first example of an X-ray crystallographic determination for an end-on orientation of C70 cocrystallized with porphyrins. On the other hand, only a side-on orientation of C70 was observed in the crystal structure of the complex of H4-CPDPy and C70. Further, a zigzag array of C70 molecules through van der Waals contacts with each other is formed along the monoclinic b axis in the latter crystal.
- 著者
- Hiroshi Ikeda Kazuki Matsuo Yasunori Matsui Masaya Matsuoka Kazuhiko Mizuno
- 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
- pp.1104260289, (Released:2011-05-07)
- 参考文献数
- 67
- 被引用文献数
- 3
The mechanism of the Cope rearrangement of 1,5-hexadienes remains controversial. Two pathways for the rearrangement of 2,5-diphenyl-1,5-hexadiene have been debated over the past several decades. The first is a concerted route that takes place via a pericyclic transition state and the other is a stepwise process via a biradical intermediate or biradicaloid transition structure. In this study, we explored a new intramolecular trapping approach to examine the possible existence of the putative biradical that might intervene in the stepwise Cope rearrangement. For this purpose, a study was carried out in which a 1,5-hexadiene, bearing two lophyl radicals at C2 and C5 positions, moieties capable of trapping a putative biradical intermediate intramolecularly, was designed, generated, and characterized both experimentally and with density functional theory.
- 著者
- Hiroki Oguri
- 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.80, no.10, pp.1870-1883, 2007-10-15 (Released:2007-10-12)
- 参考文献数
- 98
- 被引用文献数
- 13
Ciguatoxins are the major causative toxins in ciguatera seafood poisoning. The limited availability of ciguatoxins has precluded structural elucidation and development of a reliable and specific immunoassay for detecting the toxins in contaminated fish. To seek a solution for the longstanding problem of ciguatera, we addressed the synthetic challenge by utilizing rationally designed model compounds of ciguatoxins. The C2 configuration and entire absolute configuration of ciguatoxin were successfully elucidated with minutest amounts of natural toxins, using an approach which combined partial structure synthesis, microscale chemical transformations, and the CD exciton chirality method. On the basis of the absolute configuration, the partial structures of ciguatoxins were designed and synthesized as haptens for the preparation of anti-ciguatoxin antibodies. Monoclonal antibodies (mAbs) against both ends of ciguatoxin CTX3C were prepared by immunization of mice with protein conjugates of synthetic haptens of the ABCDE-ring and the IJKLM-ring, in place of the natural toxin. Haptenic groups with surface areas larger than 400 Å2 were required to produce mAbs, which could bind strongly to CTX3C itself. A direct sandwich enzyme-linked immunosorbent assay (ELISA) using these mAbs was shown to detect CTX3C at the ppb level with no cross-reactivity against other related marine toxins, including brevetoxin A, brevetoxin B, okadaic acid, or maitotoxin. In order to make the sandwich immunoassay protocol a general method for detecting other ciguatoxins congeners, the preparation of mAbs for the left-end of ciguatoxin was investigated. Expeditious synthesis of the left end of ciguatoxin with installation of the 3-butene-1,2-diol side-chain of the A-ring as well as surface plasmon resonance (SPR) analysis of the antibody–hapten interactions are also described.
- 著者
- Yasuda Yusuke
- 出版者
- Chemical Society of Japan
- 雑誌
- Bulletin of the Chemical Society of Japan (ISSN:00092673)
- 巻号頁・発行日
- vol.80, no.11, pp.2137-2144, 2007-11-15
- 著者
- Yasuda Yusuke Matsumoto Akira Oda Ryo
- 出版者
- Chemical Society of Japan
- 雑誌
- Bulletin of the Chemical Society of Japan (ISSN:00092673)
- 巻号頁・発行日
- vol.77, no.11, pp.1973-1986, 2004-11-15