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991.
Nomoto Akihiro Sakamoto Nozomi Sakai Yuta Fukumoto Keisuke Ogura Shun-Ichiro Shouhei Katao Kakiuchi Kiyomi Kikuchi Jun-ichi Yano Shigenobu Ogawa Akiya 《Research on Chemical Intermediates》2019,45(1):3-12
Research on Chemical Intermediates - Phenylalanine ester-introduced palladium(II) and platinum(II) complexes were synthesized. Taking advantage of the formation of Schiff bases by amino acids as an... 相似文献
992.
Dr. Yoshimasa Taniguchi Dr. Takashi Kikuchi Prof. Dr. Sota Sato Prof. Dr. Makoto Fujita 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(2):e202103339
Trans-iso-α-acid is one of the main contributors to the bitter taste of fresh beer and is known to transform into various derivatives during beer aging. However, structural characterization of the derivatives has been a challenging task because of the formation of too many components. Herein, we report that most of the transformation products of trans-iso-α-acid, isolated in this study in only small quantities by HPLC, can be structurally analyzed with the crystalline sponge method. Thirteen compounds, including eight that were previously unreported, have been successfully isolated and analyzed with complete assignment of their absolute configuration. This provides an improved understanding of the chemical transformations that occur during beer aging. 相似文献
993.
Wang Wei Hanai Yuichi Takenaka Chisato Tomioka Rie Iizuka Kazuya 《Journal of Radioanalytical and Nuclear Chemistry》2020,323(2):959-964
Journal of Radioanalytical and Nuclear Chemistry - 133CsCl solution was applied to the foliage of Japanese cedar (Cryptomeria japonica) and Konara oak (Quercus serrata) under field conditions to... 相似文献
994.
Dr. Kazuya Arashiba Prof. Hiromasa Tanaka Prof. Kazunari Yoshizawa Prof. Yoshiaki Nishibayashi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(59):13383-13389
Cycling between molybdenum(I)-dinitrogen and molybdenum(IV)-nitride complexes was investigated under ambient reaction conditions. A kinetic study of the second-order reaction rate for the conversion of the molybdenum-dinitrogen complex into the molybdenum-nitride complex indicates that the formation of the dinitrogen-bridged dimolybdenum complex is involved in the rate-determining step. DFT calculations indicate that the molybdenum-dinitrogen complex transforms into the molybdenum-nitride complex via direct cleavage of the nitrogen-nitrogen triple bond of the bridging dinitrogen ligand of the dinitrogen-bridged dimolybdenum complex. The corresponding reaction of the molybdenum-nitride complex transforming into the molybdenum-dinitrogen complex proceeds via the ligand exchange of ammonia for dinitrogen at the dinitrogen-bridged dimolybdenum complexes. A new modified reaction pathway has been proposed based on the findings of our experimental and theoretical results. 相似文献
995.
Dr. Kyohei Kanomata Yuki Nagasawa Yukihiro Shibata Prof. Dr. Masahiro Yamanaka Fuyuki Egawa Dr. Jun Kikuchi Prof. Dr. Masahiro Terada 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(15):3364-3372
The precise mechanism of the chiral phosphoric acid-catalyzed aldol-type reaction of azlactones with vinyl ethers was investigated. DFT calculations suggested that the reaction proceeds through a Conia-ene-type transition state consisting of the vinyl ether and the enol tautomer of the azlactone, in which the catalyst protonates the nitrogen atom of the azlactone to promote enol tautomerization. In addition, the phosphoryl oxygen of the catalyst interacts with the vinyl proton of the vinyl ether. The favorable transition structure features dicoordinating hydrogen bonds. However, these hydrogen bonds are not involved in the bond recombination sequence and hence the catalyst functions as a template for binding substrates. From the results of theoretical studies and experimental supports, the high enantioselectivity is induced by the steric repulsion between the azlactone substituent and the binaphthyl backbone of the catalyst under the catalyst template effect. 相似文献
996.
Tanaka Noriyuki Nishidate Izumi Nakano Kazuya Aizu Yoshihisa Niizeki Kyuichi 《Optical Review》2016,23(2):323-331
Optical Review - We investigated a method to evaluate the arterial inflow and the venous capacitance in the skin tissue of streptozotocin-induced type 1 diabetic rats from RGB digital color images.... 相似文献
997.
Tetsuya Yamada Norihiro Suzuki Kazuya Nakata Chiaki Terashima Nobuhiro Matsushita Kiyoshi Okada Akira Fujishima Dr. Ken-ichi Katsumata 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(11):2380-2385
Solar-driven catalysts on semiconductors to produce hydrogen are considered as a means to solve environmental issues. In this study, H2 production coupling with oxygen consumption by noble metal-free α-FeOOH was demonstrated even though the conduction band edge was lower than the reduction potential of H+ to H2. For activation of α-FeOOH, an electron donor, Hg-Xe irradiation, and low pH (ca. 5) were indispensable factors. The H2 production from H2O was confirmed by GC-MS using isotope-labeled water (D2O) and deuterated methanol. The α-FeOOH synthesized by coprecipitation method showed 25 times more active than TiO2. The photocatalytic activity was stable for over 400 h. Our study suggests that α-FeOOH known as rust can produce H2 by light induction. 相似文献
998.
Yusuke Kuramochi Dr. Atula S. D. Sandanayaka Dr. Akiharu Satake Prof. Yasuyuki Araki Prof. Kazuya Ogawa Prof. Osamu Ito Prof. Yoshiaki Kobuke Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(10):2317-2327
A mimic for nature's solar cells : Simple mixing of nonaporphyrin macrocycle N‐( 1 –Zn)3 and acceptor ligand C60–ZnP–Tripod affords a supramolecular architecture (see scheme), in which the excitation energy collected by the macrocycle is transferred efficiently to the central ZnP acceptor, inducing charge separation between the ZnP and C60 sites.
999.
Kikuchi K Ioka A Oku T Tanaka Y Saihara Y Ogumi Z 《Journal of colloid and interface science》2009,329(2):306-309
Water electrolysis is well known to produce solutions supersaturated with oxygen. The oxygen in electrolyzed solutions was analyzed with a dissolved oxygen meter and the Winkler method of chemical analysis. The concentration of oxygen measured with the dissolved oxygen meter agreed with that obtained using the Winkler method. However, measurements using a 10-fold dilution method showed a larger concentration of dissolved oxygen compared to the above methods. We developed a modified Winkler method to measure total oxygen concentration more accurately, which agreed with the results obtained from the 10-fold dilution experiment. The difference in measurements is due to the existence of oxygen nanobubbles, as confirmed by the observation of dynamic light scattering using a laser. Further analysis of the oxygen nanobubbles demonstrated that the stability of the nanobubbles was sufficient for chemical reaction and solvation to bulk solution. 相似文献
1000.
Kenji Kikuchi Mayuka Kitawaki Atsushi Suzuki Takeo Oku 《Journal of colloid and interface science》2009,338(2):480-485
By controlling both the kind of ion and the ionic strength of electrolytes in an emulsion polymerization system of vinyl pivalate containing about 1% sodium lauryl sulfate as a surfactant, nanoparticles of polyvinylpivalate having a diameter of about 25 nm were successfully prepared. The use of high concentrations of lithium chloride and lithium sulfate (1.0 mol L−1) prevented the nanoparticles from aggregating and produced nanoparticles sizes of 25–50 nm. Ammonium acetate and sodium acetate, on the other hand, accelerated the aggregate of the nanoparticles. These phenomena were examined in detail and found to be similar to the Hofmeister phenomena and the combination rule proposed by Craig et al. 相似文献