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221.
Tomohiko Ohwada Hirotaka Kagawa Hiroshi Ichikawa 《International journal of quantum chemistry》1998,68(1):65-72
Solving the constrained Hartree–Fock equation and using the method of the energy component analysis, we have determined the fundamental factor which causes the electrons at the negative center of conjugated carbanion to delocalize over the whole system. Constraint on the π-electron flow between the anion center and polyethylenic system produces the electronic state that the lone-pair electrons are localized at the anionic center. By doing so, a prominent increase in the kinetic energy of π electrons was observed. Such an increase was found to quantitatively fit in with that by the model that electrons are packed in a box. Thus, we could clearly show that delocalization of the carbanion in the polyethylenic system is brought forth by the relaxation of the kinetic energy pressure. We also examined conjugated carbodianion systems. Dianion involves repulsive interaction between anions causing less conjugation energy. Namely, conjugation itself is given by the release in the kinetic energy pressure, but, it is restrained by the electrostatic repulsion. © 1998 John Wiley & Sons, Inc. Int J Quant Chem 68: 65–72, 1998 相似文献
222.
Tomohiko Inomata Mayuka Hatano Yuya Kawai Ayaka Matsunaga Takuma Kitagawa Yuko Wasada-Tsutsui Tomohiro Ozawa Hideki Masuda 《Molecules (Basel, Switzerland)》2021,26(22)
To develop low-cost and efficient dye-sensitized solar cells (DSSCs), we designed and prepared three homoleptic Cu(I) complexes with asymmetric ligands, M1, M2, and Y3, which have the advantages of heteroleptic-type complexes and compensate for their synthetic challenges. The three copper(I) complexes were characterized by elemental analysis, UV-vis absorption spectroscopy, and electrochemical measurements. Their absorption spectra and orbital energies were evaluated and are discussed in the context of TD-DFT calculations. The complexes have high VOC values (0.48, 0.60, and 0.66 V for M1, M2, and Y3, respectively) which are similar to previously reported copper(I) dyes with symmetric ligands, although their energy conversion efficiencies are relatively low (0.17, 0.64, and 2.66%, respectively). 相似文献
223.
Yohei SAWAYA Miho SATO Masahiro ISHIZAKA Takahiro SHIBA Akira KUBO Tomohiko URANO 《Physical Therapy Research》2022,25(1):35
Objective: The maximum phonation time (MPT) is used to assess simple respiratory functions and can be performed anywhere without special instruments. We investigated the association between MPT and respiration, considering the future utilization of simple respiratory assessments during home-based physical therapy. Method: This cross-sectional study included 140 older adults enrolled in Japanese long-term care insurance (77 men, 63 women; mean age, 77.9±8.0 years). The participants performed the MPT, followed by spirometry. We analyzed the MPT of the three age groups, relative reliability of the MPT values, and the association between MPT and respiratory function. Results: We found that the MPT of older men requiring long-term care or support was related to age. The intraclass correlation coefficient of MPT was >0.8 for all groups. Only forced vital capacity was associated with MPT in the partial correlation and multiple regression analyses. Conclusion: MPT could be an alternative assessment of respiratory function in home-based physical therapy for older adults requiring long-term care or support. 相似文献
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226.
Yutaka Nishigaichi Shinji TsurutaKenji Uenaga Tomohiko AwamuraHidetoshi Iwamoto Akio Takuwa 《Tetrahedron letters》2014
Nucleophilic addition of pentadienyltin reagent toward N-(4-methoxyphenylsulfinyl)-imine was effectively accelerated by the use of InCl3 or TMSOTf as a Lewis acid. The former afforded the γ-adduct with high stereoselectivity, while the latter gave the ε-adduct with moderate stereoselectivity, depending on the reaction mechanisms. 相似文献
227.
Hydrogenated Anatase: Strong Photocatalytic Dihydrogen Evolution without the Use of a Co‐Catalyst 下载免费PDF全文
Dr. Ning Liu Christopher Schneider Dr. Detlef Freitag Dr. Umamaheswari Venkatesan Dr. V. R. Reddy Marthala Prof.Dr. Martin Hartmann Benjamin Winter Prof.Dr. Erdmann Spiecker Dr. Andres Osvet Eva M. Zolnhofer Prof.Dr. Karsten Meyer Dr. Tomohiko Nakajima Xuemei Zhou Prof.Dr. Patrik Schmuki 《Angewandte Chemie (International ed. in English)》2014,53(51):14201-14205
The high‐pressure hydrogenation of commercially available anatase or anatase/rutile TiO2 powder can create a photocatalyst for H2 evolution that is highly effective and stable without the need for any additional co‐catalyst. This activation effect cannot be observed for rutile; however, for anatase/rutile mixtures, a strong synergistic effect can be found (similar to results commonly observed for noble‐metal‐decorated TiO2). EPR and PL measurements indicated the intrinsic co‐catalytic activation of anatase TiO2 to be due to specific defect centers formed during hydrogenation. These active centers can be observed specifically for high‐pressure hydrogenation; other common reduction treatments do not result in this effect. 相似文献
228.
Cationic Ir/Me‐BIPAM‐Catalyzed Asymmetric Intramolecular Direct Hydroarylation of α‐Ketoamides 下载免费PDF全文
Tomohiko Shirai Prof. Dr. Hajime Ito Prof. Dr. Yasunori Yamamoto 《Angewandte Chemie (International ed. in English)》2014,53(10):2658-2661
Asymmetric intramolecular direct hydroarylation of α‐ketoamides gives various types of optically active 3‐substituted 3‐hydroxy‐2‐oxindoles in high yields with complete regioselectivity and high enantioselectivities (84–98 % ee). This is realized by the use of the cationic iridium complex [Ir(cod)2](BArF4) and the chiral O‐linked bidentate phosphoramidite (R,R)‐Me‐BIPAM. 相似文献
229.
Electrogenerated Chemiluminescence of Donor–Acceptor Molecules with Thermally Activated Delayed Fluorescence 下载免费PDF全文
Dr. Ryoichi Ishimatsu Dr. Shigeyuki Matsunami Takashi Kasahara Prof. Jun Mizuno Dr. Tomohiko Edura Prof. Chihaya Adachi Prof. Koji Nakano Prof. Toshihiko Imato 《Angewandte Chemie (International ed. in English)》2014,53(27):6993-6996
The electrochemistry and electrogenerated chemiluminescence (ECL) of four kinds of electron donor–acceptor molecules exhibiting thermally activated delayed fluorescence (TADF) is presented. TADF molecules can harvest light energy from the lowest triplet state by spin up‐conversion to the lowest singlet state because of small energy gap between these states. Intense green to red ECL is emitted from the TADF molecules by applying a square‐wave voltage. Remarkably, it is shown that the efficiency of ECL from one of the TADF molecule could reach about 50 %, which is comparable to its photoluminescence quantum yield. 相似文献
230.
Tomohiko Hirano Shinya Kitagawa Hajime Ohtani Takehiko Kinoshita Yuzo Ishigaki Nobuyuki Shibata Susumu Nii 《Analytical and bioanalytical chemistry》2013,405(25):8319-8326
A method for evaluating the interactions between metal ions and nonionic surfactants in aqueous solutions containing high-concentration HCl, using gas pressure-driven low-pressure high-performance liquid chromatography (LP-HPLC) as a highly acid-resistant HPLC system, was developed. To construct the LP-HPLC for this purpose, poly(styrene-co-divinylbenzene)-based low-flow-resistance monolithic columns tolerant to highly acidic conditions were prepared using low-conversion thermal polymerization. Thermal polymerization at 65 °C for 1.5 h (monomer conversions, 33 % for styrene and 59 % for divinylbenzene) allowed preparation of a column with both high separation efficiency (around 60,000 plates m?1 for alkylbenzenes) and a quite low back pressure of 0.14 MPa at a linear flow rate of 1 mm s?1 (2.8?×?10?13 m2 in permeability). The base column prepared under the above conditions was coated with a nonionic surfactant, polyoxyethylene nonylphenyl ether (PONPE, average oxyethylene unit numbers (n)?=?3, 7.5, 15, and 20), and used for evaluation of the interactions between PONPEs and metal ions in 6 M HCl. The interactions between PONPEs and Au(III), Ga(III), Fe(III), Zn(II), and Cu(II) were successfully evaluated using both breakthrough and chromatographic methods. Furthermore, a study of the effect of the polyoxyethylene (POE) chain length revealed that the use of PONPE with the longer POE moiety enhanced the magnitude of the interaction together with the increase in the amount of oxyethylene (OE) units coated on the monolith. Moreover, the interactions of metal ions with a single OE unit were almost constant in the range of n?=?7.5–20, whereas the suppression of the interaction between Au(III) with the shortest PONPE chain (n?=?3) was also observed. Figure
Acid-resistive gas pressure-driven low-pressure high-performance liquid chromatography was developed and applied to the evaluation of interactions between metal ions and nonionic surfactants in high-concentration HCl, in particular for the effect of polyoxyethylene length on the interaction. 相似文献