Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
最新号
選択された号の論文の14件中1~14を表示しています
 
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  • Hiroyuki Asanuma, Keiji Murayama, Yukiko Kamiya, Hiromu Kashida
    2018 年 91 巻 12 号 p. 1739-1748
    発行日: 2018/12/15
    公開日: 2018/12/15
    ジャーナル 認証あり

    In this account, we demonstrate that DNA duplex is an ideal scaffold for photochemistry, particularly for comparison of photochemical theory with experiments. The well-defined structure of a DNA duplex can be regarded as an aqueous one-dimensional soft crystal composed of a chromophore-like base-pair assembly. When any base pair in the duplex is replaced with a chromophore, orientation, distance, and association number of chromophores can be precisely controlled. We have developed a new methodology for introduction of chromophores into DNA duplexes using d-threoninol. By using the DNA duplex as a scaffold, experiments on exciton interactions of chromophore assemblies can be compared with molecular exciton theory. A fluorescent resonance energy transfer (FRET) system was also constructed by introducing donor pyrene and acceptor perylene into the DNA duplex using d-threoninol monomers. Using this system, we demonstrated orientation-dependent FRET. We found that theories on both exciton interaction and FRET qualitatively coincide with experimental data and revealed the limitation of the point-dipole approximation. We also evaluated the intrinsic quantum yield of photodimerization of stilbene derivatives by suppressing a side reaction. We propose that there is a correlation of quantum yield of photodimerization with the energy gap of HOMO or LUMO, a hypothesis that deserves theoretical investigation.

    We developed a methodology for introduction of chromophores into a DNA duplex using D-threoninol as a linker. Chromophores can be introduced into the DNA duplex at any position and in any number. In this account, we describe use of this system in experimental verification of theoretical predictions in photochemistry. Fullsize Image
     
 
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  • Yasuaki Einaga
    2018 年 91 巻 12 号 p. 1752-1762
    発行日: 2018/12/15
    公開日: 2018/12/15
    ジャーナル 認証あり

    It is well known that “diamond” has ultra-high hardness and low electrical conductivity. However, introducing dopants such as boron into the diamond lattice during growth can increase its conductivity. Boron-doped diamond (BDD) with high conductivity is attracting increasing attention as one of the next-generation of superior electrode materials. In particular, it is expected that BDD electrodes can help solve some of our environmental problems and also improve our quality of life through their use in biomedical devices. Here, in this article, recent developments in the electrochemical applications of boron-doped diamond (BDD) electrodes are introduced.

    Boron-doped diamond (BDD) with high conductivity is attracting increasing attention as one of the next-generation of superior electrode materials. It can solve some of our environmental problems and improve our quality of life through use in biomedical devices. Fullsize Image
     
BCSJ Award Article
  • Ngan T. K. Nguyen, Adèle Renaud, Benjamin Dierre, Barbara Bouteille, M ...
    2018 年 91 巻 12 号 p. 1763-1774
    発行日: 2018/12/15
    公開日: 2018/12/15
    ジャーナル 認証あり

    This review paper summarizes our very recent works on the synthesis of multifunctional transparent nanocomposite thin films or coatings based on metal atom clusters by an electrophoretic deposition (EPD) process. Eight different octahedral atom clusters with niobium, molybdenum or tantalum as metallic cores were used to prepare highly transparent thin films in the visible. Green, yellow, orange, red and brown colored films were successfully fabricated by coating on a transparent conductive oxide glass substrate. Transparent nanocomposite films with prominent luminescent properties were obtained by using Mo6 clusters whereas ultra-violet (UV) and near infrared (NIR) filters were realized by using Nb6 or Ta6 clusters. The EPD process appears to be a new strategy to fabricate highly transparent, homogeneous and colored nanocomposite thin films and coatings for smart windows and solar technologies in a very short time (<90 s).

    This review paper summarizes our very recent works on the synthesis of multifunctional transparent nanocomposite thin films based on metal atom clusters by an electrophoretic deposition (EPD) process. This process appears to be a new strategy to fabricate highly transparent, homogeneous and colored nanocomposite thin films and coatings for smart windows and solar technologies in a very short time (<90 s). Fullsize Image
     
 
  • Shiladitya Chatterjee, Sean C. Chapman, Barry M. Lunt, Matthew R. Linf ...
    2018 年 91 巻 12 号 p. 1775-1780
    発行日: 2018/12/15
    公開日: 2018/12/15
    ジャーナル 認証あり

    Total ion current chromatograms (TICCs) generated by liquid chromatography-mass spectrometry (LC-MS) are prone to noise from chemical and electronic sources. This noise can severely impact the detection of analytes in a mixture. Recently, we introduced a new variable selection tool based on Pattern Recognition Entropy (PRE) that selects good quality (high signal-to-noise ratio) mass chromatograms from an LC-MS dataset and thereby creates a reduced TICC with low noise and a flat background (J. Chrom. A. 2018, 1558, 21–28). PRE, which is based on Shannon’s entropy, was shown to be a straightforward and powerful shape recognition tool for this problem. However, while the chromatographic signals in the reduced TICC from PRE were well resolved, some noise remained in the TICC, which suggested that the algorithm had selected some false positives, i.e., poor quality mass chromatograms. In this paper, we report an improved version of the PRE algorithm that utilizes a second variable selection filter based on cross-correlation (CC). As a check on the ability of PRE and CC to select high quality mass chromatograms, every mass chromatogram in our data set (1451 in total) was individually inspected and rated as either high quality (green), intermediate quality (yellow), or poor quality (red). A color-coded plot of the CC value vs. the PRE value for the mass chromatograms was created, which shows that, as expected, the higher quality mass chromatograms are localized in its upper left quadrant, which corresponds to lower PRE values and higher CC values. In our original paper on this topic, we recommended a threshold of 0.5 σ for PRE, which caused the algorithm to select 151 mass chromatograms out of 1451. Of these, 98 were of high quality, 6 were of intermediate quality, and 47 were of poor quality. Using a second threshold for CC, the algorithm retains all the high and intermediate quality mass chromatograms, while removing all 47 of the poor quality ones. The resulting TICC from the PRE-CC algorithm shows less noise compared to the TICC generated from the PRE approach alone. The PRE-CC algorithm is arguably a faster, simpler and more intuitive approach as compared to the widely used CODA_DW algorithm.

Account/Review for Materials Innovation
  • Tetsu Yonezawa, David Čempel, Mai Thanh Nguyen
    2018 年 91 巻 12 号 p. 1781-1798
    発行日: 2018/12/15
    公開日: 2018/12/15
    ジャーナル 認証あり

    In the past decades, various nanomaterials have been intensively developed because of their unique electrical, optical, magnetic as well as catalytic properties. In this review, we discuss the plasma-in-liquid process, especially the microwave-induced plasma-in-liquid process (MWPLP), for metal and metal oxide nanoparticle production. Various types of plasma systems have been employed to produce metal, alloy, and metal oxide nanoparticles. Nanoparticle production by plasma processes usually requires fewer chemical additives compared to other chemical processes. After discussing the bottom-up approach and the plasma-in-liquid process for nanoparticle synthesis, we have focused on MWPLP. Various apparatus systems and detailed mechanisms of MWPLP will be discussed and preparation of metal and metal oxide nanoparticles by MWPLP will be introduced in detail. The surface-coated-electrode system, which is a unique system for MWPLP, is also discussed in this review. This system prevents sample contamination due to the metal components, which are usually ejected into the surrounding liquid after plasma ignition during the production of nanoparticles.

    We discuss the plasma-in-liquid process, especially the microwave-induced plasma-in-liquid process (MWPLP), for metal and metal oxide nanoparticle production. Various types of plasma systems have been employed to produce metal, alloy, and metal oxide nanoparticles with very short time. Detailed structural consideration of the obtained nanoparticles will also be discussed. Fullsize Image
     
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