Bulletin of the Chemical Society of Japan
Online ISSN : 1348-0634
Print ISSN : 0009-2673
ISSN-L : 0009-2673
Current issue
Showing 1-21 articles out of 21 articles from the selected issue
Account/Review for Life Chemistry
  • Sairan Eom, Goeun Choi, Hiroyuki Nakamura, Jin-Ho Choy
    2020 Volume 93 Issue 1 Pages 1-12
    Published: January 15, 2020
    Released: January 15, 2020
    JOURNALS RESTRICTED ACCESS

    In the last several decades, 2-dimensional (2D) nanomaterials have been studied in various bio-fields such as drug delivery systems, diagnostic and imaging materials, etc. In particular, many investigations have been intensively conducted to explore 2D nanomaterials for drug delivery devices such as layered double salts (LDSs), layered rear-earth hydroxides (LRHs), and layered double hydroxides (LDHs) due to their low toxicity, high solubility in body fluid, high tumor targeting efficiency, large drug loading capacity, etc. However, only a few reports have been made to date on diagnostic and imaging effects on those 2D nanomaterials. In this review, therefore, an attempt is made to underline how important such 2D nanoparticles would be applicable for optical imaging, magnetic resonance imaging (MRI), single photon emission computed tomography (SPECT), positron emission tomography (PET), computed tomography (CT), etc., and to discuss on their potential molecular imaging modalities for image-guided and precision therapy as well.

    In this review, we address 2-dimensional layered hydroxides with low toxicity, high solubility in body fluid, high tumor targeting efficiency and large drug loading capacity, etc. And we highlight its recent advances for diagnosis and imaging functions, and try to provide outlook on possible future progress and challenges in the view point of nanomedicine. Fullsize Image
     
 
  • Tomoki Kanazawa, Miharu Eguchi, Shunsuke Nozawa, Kazuhiko Maeda
    2020 Volume 93 Issue 1 Pages 13-19
    Published: January 15, 2020
    Released: January 15, 2020
    JOURNALS RESTRICTED ACCESS

    Spinel-type Co-Al-Cr mixed oxides (CoAl2−xCrxO4) were developed as electrochemical water oxidation catalysts. CoAl2−xCrxO4 powders were synthesized by a sol-gel method, followed by calcination at elevated temperatures in air. Electrochemical water oxidation was conducted in a phosphate-buffered aqueous solution (pH 7.5) using CoAl2−xCrxO4-loaded fluorine-doped tin oxide (FTO) conductive glass support under potentiostatic control. The electrochemical water oxidation activity was enhanced by substitution of Cr3+ ions for B-site Al3+ in CoAl2O4 in all activity metrics (i.e., geometric, specific and mass activities). Among the Cr-substituted CoAl2O4 examined, the highest activity was obtained for CoAl1.6Cr0.4O4, which was stable at +1.80 V (vs. RHE) for the generation of O2 with a Faradaic efficiency of close to unity and with minimal impact of undesirable Cr3+ oxidation. Physicochemical analyses by means of transmission electron microscopy, X-ray absorption spectroscopy, and electrochemical impedance spectroscopy indicated that the key to achieve high geometric activity was a reduction in the resistance of the electrode by the use of high surface area CoAl2−xCrxO4, which was achieved by controlling the preparation conditions of CoAl2−xCrxO4, i.e., appropriate adjustment of the Cr concentration and the calcination temperature.

  • Asuka Namai, Koreyoshi Ogata, Marie Yoshikiyo, Shin-ichi Ohkoshi
    2020 Volume 93 Issue 1 Pages 20-25
    Published: January 15, 2020
    Released: January 15, 2020
    JOURNALS RESTRICTED ACCESS

    High-speed wireless communication plays a significant role in the Internet of Things (IoT) era. 120-GHz and 140-GHz band millimeter waves have potential in broadcasting wireless communications, wireless data transmissions between cellular base stations, and traffic monitoring sensors in intersection areas for advanced driver assistance systems (ADAS). Herein we report a magnetic millimeter wave absorber composed of TiIV–CoII substituted ε-Fe2O3, which is a series of ε-(TiIVCoII)xFeIII2−2xO3 nanomagnets (0 ≤ x ≤ 0.048). ε-(TiIVCoII)xFeIII2−2xO3 shows magnetic hysteresis loops, and the coercive field changes from 20.0 kOe (x = 0) to 8.4 kOe (x = 0.048) with increasing x. Terahertz time domain spectroscopy (THz-TDS) measurements show that ε-(TiIVCoII)xFeIII2−2xO3 exhibits millimeter wave absorption peaks at 140 GHz with full width at half maximum (Δf) = 15 GHz for x = 0.033 and at 121 GHz with Δf = 24 GHz for x = 0.048. These broadband absorptions are useful for noise suppression over a wide frequency range.

  • Fan Gan, Ningning Dong, Zhiwei Liu, Huimei Jia, Jun Wang, Yu Chen
    2020 Volume 93 Issue 1 Pages 26-31
    Published: January 15, 2020
    Released: January 15, 2020
    JOURNALS RESTRICTED ACCESS

    Molybdenum disulfide (MoS2) nanosheets are insoluble in any organic solvent, which makes them more difficult to fabricate into thin film devices for nanoelectronics and nonlinear optics. To solve practical solution-processability problems of the MoS2 nanosheets, it would be ideal and feasible to design and synthesize MoS2-based solution-processed organic/polymeric materials. In this work, new organic small molecule covalently modified MoS2 nanosheets (MoS2-CHT) were synthesized through a simple reaction between MoS2 and 6-(9H-carbazol-9-yl)hexane-1-thiol (CHT). Both a DMF solution of MoS2-CHT and a MoS2-CHT/PMMA film exhibited excellent nonlinear optical (NLO) and optical limiting (OL) responses when compared to the MoS2 and MoS2/CHT mixture. As a result, among these materials, the annealed MoS2-CHT/PMMA film showed the largest nonlinear absorption coefficients (βeff) and highest imaginary third-order susceptibilities (Imχ(3)) (997.75 cm/GW and 4.25 × 10−10 esu at 532 nm; 372.62 cm/GW and 3.19 × 10−10 esu at 1064 nm). The enhanced NLO/OL performance of the annealed film could be due to the structural transition of MoS2 in MoS2-CHT from the 1T phase to the 2H phase during the annealing and the possible thermal-induced electron transfer effect between MoS2 and CHT moieties in MoS2-CHT.

  • Isao Shitanda, Takanao Kato, Ryo Suzuki, Tatsuo Aikawa, Yoshinao Hoshi ...
    2020 Volume 93 Issue 1 Pages 32-36
    Published: January 15, 2020
    Released: January 15, 2020
    JOURNALS RESTRICTED ACCESS

    Poly(glycidyl methacrylate) (poly(GMA)) bearing pendant glycidyl groups, grafted on the surface of MgO-templated carbon (MgOC), is useful for forming strong multipoint covalent bonds with amino functional groups on the surface of flavin adenine dinucleotide-dependent glucose dehydrogenase (FAD-GDH) molecules. The immobilized FAD-GDH can generate glucose-oxidation catalytic current using 1,2-naphthoquinone (12NQ) as the redox mediator, which is also captured on the electrode surface. The catalytic current is more stable than that obtained using the FAD-GDH-MgOC electrode without poly(GMA) because the leaching of FAD-GDH and 12NQ is suppressed by the enzyme capping effect.

  • Masakuni Takahashi, Koji Ohara, Kentaro Yamamoto, Tomoki Uchiyama, Haj ...
    2020 Volume 93 Issue 1 Pages 37-42
    Published: January 15, 2020
    Released: January 15, 2020
    JOURNALS RESTRICTED ACCESS

    The correlation between the Pt–Pt interatomic distance of a Pt/C catalyst and the specific activity of the oxygen reduction reaction is discussed. Total X-ray scattering measurement coupled with pair distribution function (PDF) analysis was performed to obtain subsurface information of the Pt/C catalyst, which can obtain a much longer interatomic distance than X-ray absorption fine structure (XAFS) measurement. The subsurface structure of the catalyst was previously discussed on the basis of simulations with three-dimensional complex models. In this study, the subsurface structure of Pt–Pt bonds in the catalyst could be easily obtained from experimental data by simple model fitting using the PDF. Results based on XAFS measurement showed no correlation with the specific activity. In contrast, the obtained Pt–Pt interatomic distances in the subsurface using PDF showed a strong negative correlation with the specific activity as in a previous study.

  • Shu-Rong Chen, Yi Li, Bi-Yu Wu, Hui Xu
    2020 Volume 93 Issue 1 Pages 43-49
    Published: January 15, 2020
    Released: January 15, 2020
    JOURNALS RESTRICTED ACCESS

    By employment the heterometallic strategy, a new highly porous metal-organic framework {(Me2NH2)[Mn3K2(TZIA)3(H2O)3]·(DMF)4}n (1) was prepared via corresponding K(I)and Mn(II) salts and hetero-donor organic ligand 5-(1H-tetrazol-5-yl)isophthalic acid (H3TZIA) via solvothermal conditions in water and DMF mixed solvent. X-ray study of a single crystal shows that ionic K+ was immobilized on the surface of pores via trinuclear Mn2+–tetrazole coordination motif. The resulting activated 1a has been explored in detail by BET analysis to probe its porosity. The removal of water molecules in order to generate 1a makes it possible for K+ ions to be applied as an efficient and size-selective multiphase catalyst for cyanosilylation of acetaldehyde under the mild conditions without solvent. Furthermore, ELISA assay was performed to measure IL-18 and IL-1β level in hCMEC/D3 human brain microvascular endothelial cells after compound treatment. Besides, ROS detection and RT-PCR was performed to detect ROS production as well as the related gene expression. Next, the protective effect of the compound was evaluated in animal model in vivo.

  • Kento Iwai, Soichi Yokoyama, Haruyasu Asahara, Nagatoshi Nishiwaki
    2020 Volume 93 Issue 1 Pages 50-57
    Published: January 15, 2020
    Released: January 15, 2020
    JOURNALS RESTRICTED ACCESS

    A systematic study of non-electronic activation of an aromatic ring was performed using a series of 8-substituted 1-methylquinolinium salts. As the 8-substituent became bulkier, the quinoline framework was distorted by steric repulsion between substituents at the 1- and 8-positions. This was accompanied by lack of coplanarity, which brought about dearomatization. Consequently, quinolinium ions possessing a bulky 8-substituent exhibited high reactivity undergoing nucleophilic addition at the 2-position efficiently. We demonstrate that the activation was achieved sterically and not electronically.

  • Tomoki Nishi, Daiki Muko, Janice B. Rabor, Yasuro Niidome
    2020 Volume 93 Issue 1 Pages 58-64
    Published: January 15, 2020
    Released: January 15, 2020
    JOURNALS RESTRICTED ACCESS

    Gold nanospheres were dispersed in gelatin sections (10–100 µm thickness) and their laser desorption/ionization (LDI) efficiencies of gold ions (Au+, Au2+, Au3+) under pulsed-laser irradiation were examined. The mass signal intensities were linear to the surface densities ranging from 6 × 104 to 6 × 106 particles/mm2. When the thickness of the sections was thinner than or equal to 50 µm, the LDI efficiency of gold nanospheres was independent of the thickness. Thus, the mass intensity was dependent on the surface densities of gold nanospheres in the gelatin sections. It was also found that the LDI efficiencies were affected by the concentration of gelatin solutions. Based on the high reproducibility of mass signals obtained from gelatin sections, the LDI efficiencies of star-shaped gold nanoparticles (gold nanostars) were also evaluated. It was found that the nanostars showed higher LDI efficiencies than gold nanospheres, but the enhancement was not more than 25%.

  • Shinji Toyota, Kan Wakamatsu
    2020 Volume 93 Issue 1 Pages 65-75
    Published: January 15, 2020
    Released: January 15, 2020
    JOURNALS RESTRICTED ACCESS

    The structures and conformation of anthracene-2,7-diyl cyclic oligomers were investigated by DFT calculations. The energy minimum and transition state structures of the oligomers ranging from pentamer to nonamer were optimized at the M05-2X/6-31G(d) level. The mechanisms of conformational interconversion were analyzed on the basis of the calculated structures and the thermodynamic energies. The number of structures and the conformational flexibility rapidly increased with increasing ring size. In the stable structures, the dihedral angles between the anthracene units were ca. ±40° or ±140°, and the obtuse angles appeared only in large oligomers. We estimated the cavity size of the cyclic oligomers from the calculated structures and their strain energies by thermochemical calculations of the homodesmotic reactions.

Account/Review for Life Chemistry
  • Hideki Kandori
    2020 Volume 93 Issue 1 Pages 76-85
    Published: January 15, 2020
    Released: January 15, 2020
    JOURNALS RESTRICTED ACCESS

    Rhodopsins, which are also called retinal proteins, are photoreceptive proteins. Their photoreactions have attracted many researchers in physics, chemistry and biology. In addition, they are now used as key tools in optogenetics. Although rhodopsin was originally named as a red-colored pigment for vision, the modern meaning of rhodopsin encompasses photoactive proteins containing a retinal chromophore in animals and microbes. Animal and microbial rhodopsins possess 11-cis and all-trans retinal, respectively, to capture light in seven transmembrane α-helices, and photoisomerizations into all-trans and 13-cis forms, respectively, initiate each function. Unlike animal rhodopsins, several kinds of microbial rhodopsins are able to transport ions in a passive or an active manner, and light-gated channels or light-driven pumps, respectively, are the main tools in optogenetics. In this article, historical aspects and recent advances of retinal protein research are reviewed. After general introduction of rhodopsins, the molecular mechanism of bacteriorodopsin, a light-driven H+ pump and the best studied microbial rhodopsin, is described. Then, molecular properties and several variants of channelrhodopsin, the light-gated ion channel, are introduced. As history has proven, understanding the molecular mechanism of microbial rhodopsins is a prerequisite for useful functional design of optogenetics tools in future.

    Rhodopsins, also called retinal proteins, are composed of animal and microbial rhodopsins, which contain 11-cis and all-trans retinal, respectively. Unlike animal rhodopsins, microbial rhodopsins are able to transport ions, which have been used as the main tools in optogenetics. This reviews historical aspects and recent advances of the retinal protein research. Fullsize Image
     
 
  • Shoji Ishizaka, Fangqin Guo, Xiaomeng Tian, Samantha Seng, Yeny A. Tob ...
    2020 Volume 93 Issue 1 Pages 86-91
    Published: January 15, 2020
    Released: January 15, 2020
    JOURNALS RESTRICTED ACCESS

    A novel experimental approach to study the hygroscopic properties of multi-component inorganic aerosols was demonstrated using a laser trapping technique. The efflorescence and deliquescence phase transitions of the equimolar mixture of NaCl and NaNO3 particles levitated in air were reversibly induced by controlling relative humidity. The two-stage phase transitions of the particles during the dehumidifying and humidifying processes were successfully observed in air. To our knowledge, this is the first experimental result to observe the reversible hygroscopic behavior of single optically-levitated multi-component inorganic aerosols in air. Furthermore, to elucidate the influence of solid substrates on the homogeneous and heterogeneous nucleation processes, the efflorescence relative humidity (ERH) and mutual efflorescence relative humidity (MERH) in air were compared with those observed on a hydrophobic glass substrate. The average ERH and MERH values of the NaCl–NaNO3 particles levitated in air were lower than those obtained for the particles deposited on the hydrophobic glass substrate.

  • Di Wang, Bin Zhang, Lin-Fen Xu, Ling-Na Huang
    2020 Volume 93 Issue 1 Pages 92-98
    Published: January 15, 2020
    Released: January 15, 2020
    JOURNALS RESTRICTED ACCESS

    A new luminescent In(III)-based coordination polymer with the chemical formula of {[In(ipa)(H2O)](H2O)(CH3CN)2}n (1, H3ipa = 5-hydroxyisophthalate) has been successfully prepared via a solvothermal reaction of H3ipa and In(NO3)3·6H2O in CH3CN and DMF mixed solvent. The strong emission of 1 could be quenched efficiently by trace amounts of Cr2O72−, while other competing analogues show no such quenching effect, indicating complex 1 could be applied as an effective sensor for the detection of Cr2O72− in the solution. To solve the problem of bacterial infection after missed abortion, the protective effect of the compound in vivo was further explored. CFU detection was carried to evaluate the inhibitory effect of compound on bacterial numbers, and then ELISA was conducted to detect the level of IL-18 and IL-1β in the infectious tissues. The pharmacokinetic detection of the compound was also performed in SD rats. The results obtained from molecular docking and pose scoring software exhibited a possible binding mode of the compound binding to NFκB, which might provide potential regulation mechanisms for the compound.

  • Shotaro Nakamura, Michitaka Okamoto, Norimitsu Tohnai, Ken-ichi Nakaya ...
    2020 Volume 93 Issue 1 Pages 99-108
    Published: January 15, 2020
    Released: January 15, 2020
    JOURNALS RESTRICTED ACCESS

    Trioxa- and trithia-truxene derivatives, 3,8,13- (para) and 2,7,12- (meta) tri-tert-butylated benzo[1,2-b:3,4-b′:5,6-b′′]-trifuran and -tris[1]benzothiophenes (p-tBuTxO, m-tBuTxO, p-tBuTxS, and m-tBuTxS), have been prepared by palladium-catalyzed intramolecular triple dehydrogenative cyclization. While these compounds are soluble in common organic solvents, they have high melting points, mostly more than 300 °C. m-tBuTxO shows a substantial solid state UV fluorescence with a higher quantum efficiency than p-tBuTxO. Both p-tBuTxS and m-tBuTxS, however, exhibit only weak fluorescence in both solution and solid state (the λmax of emission in solid state specifically depends on the substitution pattern), but obvious blue phosphorescence is observed in PMMA film under vacuum at r.t. as well as in MeCy at 77 K, which is attributable to the heavy atom effect of sulfur. Meanwhile, p-tBuTxS exhibits a higher hole mobility compared with that of m-tBuTxS in the evaluation of thin-film FET characteristics. These results are discussed in terms of intrinsic molecular structures and arrangements determined by X-ray crystallography.

Account/Review for Life Chemistry
Award Account
  • Yuki Yamada
    2020 Volume 93 Issue 1 Pages 109-118
    Published: January 15, 2020
    Released: January 15, 2020
    JOURNALS RESTRICTED ACCESS

    The basic formula of Li-ion battery electrolytes (i.e., LiPF6 and ethylene carbonate) has remained unchanged ever since commercialization in the early 1990s. However, toward advanced batteries with higher energy density and higher safety, a new electrolyte design that leads to better functions is required. Recently, various new functions have been discovered for highly concentrated electrolytes (over 3 mol dm−3 (M) vs. standard 1 M), which arises from their unique coordination states of ions and solvent molecules. Based on this achievement, the coordination states are increasingly recognized as key to further functionalizing battery electrolytes. This account introduces an electrolyte design based on the coordination states and provides future visions on rechargeable batteries that will be realized thereby.

    Concentrated battery electrolytes have been outside the focus of research because of their decreased ionic conductivity. However, various unusual properties and functions have been recently discovered, which arise from their unique coordination states. This account introduces our original contributions to the development of concentrated electrolytes and provides future visions on advanced batteries using this new concept of electrolyte. Fullsize Image
     
 
  • Atsushi Sugita, Miwa Tsuruoka, Yuta Kinoshita, Yushi Futagami, Tomoyuk ...
    2020 Volume 93 Issue 1 Pages 119-126
    Published: January 15, 2020
    Released: January 15, 2020
    JOURNALS RESTRICTED ACCESS

    We present the orientation order of push-pull chromophores consisting of phenyl vinylene thiophene vinylene (FTC) bridges between the N,-N-bis-(2-hydroxyethyl)-amine electron donor and phenyl-trifluoromethyl-tricyanofuran (TCF-Ph-CF3) acceptor in poly (methyl methacrylate) (PMMA). The chromophores have attracted great attention as a guest material for nonlinear optical polymers for near-IR applications. Our experimental results demonstrated that the chromophores with relatively large molecular weights were oriented in a polar order with the aid of adsorption onto the surfaces of the SiO2 substrates, even without the conventional electrical poling procedure. The polar order of the chromophores extended approximately 50 nm vertically from the substrate surfaces. Polarized linear absorption and second harmonic generation spectroscopies were performed to determine the orientation distribution function of the chromophores in the PMMA. The average molecular tilt angle Θ, indicating the degree of the orientation order, was wider than the magic angle, and the chromophores were preferably oriented horizontally to the substrate surfaces. A relatively low orientation order was explained in terms of the strong dipole-dipole repulsions among the neighboring guest chromophores.

  • Akinari Umemoto, Yasuomi Yamazaki, Daiki Saito, Yusuke Tamaki, Osamu I ...
    2020 Volume 93 Issue 1 Pages 127-137
    Published: January 15, 2020
    Released: January 15, 2020
    JOURNALS RESTRICTED ACCESS

    Supramolecular photocatalysts, which consist of redox photosensitizer and catalyst units, have recently attracted attention in the field of artificial photosynthesis. Aiming to construct a durable supramolecular photocatalyst for CO2 reduction, a new Re–Ru–Re trinuclear complex was successfully developed, where one Ru unit, acting as photosensitizer, was linked to two Re units, acting as catalysts, through ethylene chains. The novel complex was synthesized by creating two chelate moieties on the ligand of a Ru complex using the Negishi-coupling reaction, which were then coordinated to Re complexes. This trinuclear complex selectively photocatalyzed the reduction of CO2 to CO under visible light irradiation, with high durability compared with the corresponding Ru–Re binuclear complex and a mixed system of model mononuclear complexes. Absorption spectra and mass spectroscopic data of the reaction solutions revealed a rapid consumption of the electrons on the one-electron reduced species of the Ru unit, which led to suppression of the Ru unit decomposition, thereby maintaining its photosensitizing ability and product selectivity.

Account/Review for Life Chemistry
Award Account
  • Takahiro Muraoka
    2020 Volume 93 Issue 1 Pages 138-153
    Published: January 15, 2020
    Released: January 15, 2020
    JOURNALS RESTRICTED ACCESS

    This account focuses on synthetic approaches to develop functional molecules on the basis of mimicry and manipulation of proteins. Proteins are one of the central molecules serving vital functions and maintaining biological homeostasis. The sophisticated roles and dynamic functions found in proteins provide lots of useful clues to develop synthetic functional molecules. This account describes the development of synthetic supramolecular ion channels made of multiblock structures that can switch ion transportation in response to external stimuli by mimicking ligand-gated and mechano-responsive transmembrane proteins. Multiblock amphiphiles also perform membrane budding and self-assembly in a bilayer. This account also describes functionalization of poly(ethylene glycol) by structuring, which allows for controlling the thermal properties and protein aggregation suppression. The thermal response of poly(ethylene glycol) is also effective in a solid state to develop crystals showing thermal polymorphic transitions.

    This account describes synthetic approaches to develop functional molecules based on the concept to mimic and manipulate proteins. Inspired by the multiblock structures seen in transmembrane proteins, synthetic supramolecular ion channels that respond to ligand and membrane tension are developed. Functionalization of poly(ethylene glycol) by structuring allows for controlling the thermal properties and protein aggregation suppression. Fullsize Image
     
 
  • Masashi Hasegawa, Masahiko Iyoda
    2020 Volume 93 Issue 1 Pages 154-162
    Published: January 15, 2020
    Released: January 15, 2020
    JOURNALS RESTRICTED ACCESS

    The self-assembly and electrochromic nanofiber formation of radially π-extended tetrathiafulvalene (TTF) tetramers anchored to 1,2,4,5-tetraethynylbenzene were investigated. The tetramer with SBu-substituents underwent self-assembly in solution. Cationic species of the tetramer, obtained by chemical oxidation with Fe(ClO4)3, exhibited a marked electrochromism in the solution. Their electronic spectra revealed absorption bands corresponding to intermolecular mixed-valence aggregation based on (TTF//TTF)•+, and π-aggregation based on (TTF•+//TTF•+) due to the strong molecular association in the cationic species. Furthermore, the tetramer formed an entangled nanoscale fibrous material from CHCl3–hexane. Electrochemical oxidation of the nanofiber on an indium tin oxide electrode revealed a repeatable redox profile. The nanofiber displayed remarkable electrochromic behavior: the color of the fiber changed from purple (neutral) to brown/brownish green (dication and trication) and green (tetracation). These color changes of the nanofiber are similar to those in solution, and the electronic spectra of the oxidized nanofibers reflected the stacked TTF units in the cationic nanofibers.

  • Bokeun Kim, Makoto Nakatsuji, Takuya Mameda, Takeshi Kubota, Morifumi ...
    2020 Volume 93 Issue 1 Pages 163-175
    Published: January 15, 2020
    Released: January 15, 2020
    JOURNALS RESTRICTED ACCESS

    Enantioselective hydrogenations of α,β-unsaturated carboxylic acids over cinchona alkaloid-modified Pd metal heterogeneous catalysts have received considerable attention because of scientific importance in molecular recognition catalysis as well as feasibility of industrial applications. In the present study, comprehensive kinetic analysis of the hydrogenation was conducted to disclose the crucial kinetic parameters controlling enantiodifferentiation and reaction rate with the combinations of four kinds of modifier and three kinds of substrate. Despite simplicity of the kinetic model, the present novel kinetic formulation allows us to describe the enantioselectivity as a function of modifier concentration, to estimate intrinsic enantioselectivity at the modified sites, to estimate respective reaction rates at the modified and unmodified sites, and to establish a correlation between the magnitude of ligand acceleration and kinetic parameters. The enantioselectivity is successfully correlated to the reaction rate. The adsorption strength of the modifier on Pd is suggested to decrease in the order, cinchonidine > cinchonine > quinine > quinidine. The roles played by benzylammine and the observed decrease in the selectivity at a high modifier concentration are also discussed. The kinetic model and formulation can be applied to analyze the catalytic behaviors and performance of Pt counterparts.

BCSJ Award Article
  • Yang Li, Joel Henzie, Teahoon Park, Jie Wang, Christine Young, Huaqing ...
    2020 Volume 93 Issue 1 Pages 176-181
    Published: January 15, 2020
    Released: January 15, 2020
    JOURNALS RESTRICTED ACCESS

    Miniaturized power supplies, such as microsupercapacitors, are highly demanded in micro-electro mechanical systems (MEMS) and micro portable microdevices due to their superior cyclability, high power density, and considerable energy. In this study, we utilize ZIF-8 derived carbon as a source of active material to fabricate flexible microsupercapacitors via a simple electrophoresis method. The deposited ZIF-8 derived carbon particles with high surface area play a decisive role in achieving high electrochemical performances. The simple and straightforward process of electrophoretic deposition using ZIF-8 derived carbon particles generates porous carbon films on microsupercapacitors, which leads to a superior electrochemical performance.

    In this study, we utilize ZIF-8 derived carbon as a source of active material to fabricate flexible microsupercapacitors via electrophoresis method. The deposited ZIF-8 derived carbon particles with high surface area play a decisive role in achieving high electrochemical performances. Fullsize Image
     
feedback
Top