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381.
Design and Synthesis of Perpendicularly Connected Metal Porphyrin–Imide Dyads for Two‐Terminal Wired Single Molecular Diodes 下载免费PDF全文
Murni Handayani Syun Gohda Dr. Daisuke Tanaka Prof. Takuji Ogawa 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(25):7655-7664
Four different porphyrin–imide dyads bearing different central metals (zinc or rhodium) and different substituents on the porphyrin macrocycles (tert‐butyl or methoxy) were synthesized for single molecular diode measurements. The molecules were designed to separate the donor component (porphyrin) from the acceptor component (imide) by bonding in a perpendicular arrangement, thus enhancing the rectification properties. UV/Vis absorption spectra and density functional theory calculations showed that the design was successful and that the molecular orbitals of the dyads were the summation of the two components, with minimal interaction between them. The effect of the central metal was found to be significant, with the lowest energy absorption for the zinc dyads being attributed to the mixed state of charge transfer from porphyrin to imide and the Q band, whereas that of the rhodium dyads indicated insignificant charge‐transfer character. 相似文献
382.
Cover Picture: Switching of Single‐Molecule Magnetic Properties of TbIII–Porphyrin Double‐Decker Complexes and Observation of Their Supramolecular Structures on a Carbon Surface (Chem. Eur. J. 36/2014) 下载免费PDF全文
383.
Dr. Daisuke Asakura Dr. Eiji Hosono Dr. Miho Kitamura Dr. Koji Horiba Dr. Eisuke Magome Dr. Hiroyuki Setoyama Dr. Eiichi Kobayashi Dr. Hayato Yuzawa Dr. Takuji Ohigashi Dr. Takaaki Sakai Dr. Ryoichi Kanega Dr. Takashi Funaki Dr. Yukari Sato Dr. Akihiro Ohira 《化学:亚洲杂志》2023,18(1):e202201047
We performed X-ray absorption studies for the electrolytes of a Ti−Mn redox flow battery (RFB) to understand the redox reaction of the Ti/Mn ions and formation of precipitates in charged catholyte, because suppression of the disproportionation reaction is a key to improve the cyclability of Ti−Mn RFB and enhance the energy density. Hard X-ray absorption spectroscopy with a high transmittance and soft X-ray absorption spectroscopy to directly observe the 3d orbitals were complementarily employed. Moreover, the Ti/Mn 3d electronic structure for each precipitate and solution in the charged catholyte was investigated by using scanning transmission X-ray microscopy: the valence of Mn in the precipitate is mostly attributed to 4+, and the solution includes only Mn2+. This charge disproportionation reaction should occur after the Mn ions in the catholyte should be oxidized from Mn2+ to Mn3+ by charge. 相似文献
384.
Dr. Masahiro Hayakawa Mayu Kameda Ryosuke Kawasumi Dr. Soichiro Nakatsuka Dr. Nobuhiro Yasuda Prof. Dr. Takuji Hatakeyama 《Angewandte Chemie (International ed. in English)》2023,62(14):e202217512
Organic light-emitting diodes (OLEDs) receive considerable attention because of their commercial use in flat panel displays. Herein, highly efficient spiroborate-based host materials are reported for use in blue OLEDs. Our designed spiroborates ( SBOX ) were simple to synthesize and exhibited high triplet excitation energies, narrow S-T gaps, and balanced charge carrier mobilities. A blue OLED containing one of the designed spiroborates, SBON , as a host exhibited a high external quantum efficiency (27.6 %) and low turn-on voltage (3.7 V) compared to those observed using 3,3′-di(9H-carbazol-9-yl)-1,1′-biphenyl (17.6 % and 4.5 V, respectively), indicating their potential as host materials in OLEDs. 相似文献
385.
Dr. Sayuri L. Higashi Yuki Shintani Prof. Masato Ikeda 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(48):e202201103
Artificially synthesized stimuli-responsive biomolecules are attractive as molecular tools for monitoring and modulating biological systems. In biological systems, redox stimuli are common, and their dysregulation is typically linked to various abnormal or disease states. In this Concept article, the molecular design of reduction-responsive biomolecules, such as peptides, nucleic acids, and saccharides, which are produced by introducing nitroaryl groups into them, is reviewed with a special emphasis on simple 4-nitrobenzene-based motifs. 相似文献
386.
Takuji Magata Saeka Nagano Takuya Endo Jun Kawaida Shiho Nagaoka Yoshimi Hirokawa Naoyoshi Maezaki 《Tetrahedron letters》2017,58(37):3628-3630
Methyl 2-[1-[(tert-butoxycarbonyl)amino]ethyl]-4-methyloxazole-5-carboxylate (1) was synthesized with high optical purity via a Pd–catalyzed amide coupling with vinyl triflate with subsequent oxazole formation. The latter reaction proceeds via bromination of an enamide with NBS and DBU-promoted cyclization. The oxazole subunit positional isomer in a macrocyclic azole peptide was obtained in a good yield without racemization. The scope and limitations of this reaction were also investigated. 相似文献
387.
Satoru Sato Kenji Shintani Naokazu Idota Takashi Nishino Yoshiyuki Sugahara 《Cellulose (London, England)》2017,24(12):5463-5473
Transparent organic–inorganic hybrids with a whitish colour were prepared from cellulose diacetate (CDA) nanosheets derived from Dion–Jacobson-type ion-exchangeable layered perovskite HLaNb2O7·xH2O (HLaNb) to prepare CDA-based hybrids bearing covalent bonds between HLaNb nanosheets and CDA matrices for improved mechanical properties. An n-decoxy derivative of HLaNb (C10_HLaNb) was exfoliated in acetonitrile by ultrasonication. TEM and AFM images revealed that C10_HLaNb was exfoliated into individual nanosheets. In order to explore the local environment around HLaNb nanosheets, a very small amount of CDA was reacted with a C10_HLaNb nanosheet dispersion [molar ratio COH:(NbOH + NbOC10H21) = 4:1] at 80 °C, and solid-state 13C NMR with cross polarization and magic angle spinning techniques showed that an alcohol-exchange-type reaction was proceeded to graft the CDA chains to the HLaNb nanosheets via new Nb–O–C covalent linkages. The CDA-based hybrids were prepared by dispersing 5 mass% of HLaNb nanosheets in CDA and subsequent heating at 80 °C for 1–7 days to cause a grafting reaction, and the product prepared by a 1-day grafting reaction exhibited improved mechanical properties compared to neat CDA; the Young’s modulus, tensile strength and toughness increased by 18, 34 and 78%, respectively. The mechanical properties deteriorated with further extension of the reaction period, however. In addition, a hybrid film prepared by mixing CDA and a C10_HLaNb nanosheet dispersion exhibited only a slight improvement in mechanical properties. These results clearly indicate that formation of an appropriate number of Nb–O–C bonds at the nanosheet/CDA interfaces is effective for improving mechanical properties. 相似文献
388.
T Mimoto J Imai S Tanaka N Hattori O Takahashi S Kisanuki Y Nagano M Shintani H Hayashi H Sakikawa 《Chemical & pharmaceutical bulletin》1991,39(9):2465-2467
A novel class of HIV-1 protease inhibitors containing a hydroxymethylcarbonyl (HMC) isostere were designed from the substrate transition state and synthesized. Phenylnorstatine [Pns; (2R,3S)-3-amino-2-hydroxy-4-phenylbutyric acid] and the 2S diastereomer, (2S,3S)-3-amino-2-hydroxy-4-phenylbutyric acid, named allophenylnorstatine (Apns) were effective transition-state mimics, and incorporation of Pns-Pro or Apns-Pro at the P1-P1' site gave potent and specific HIV-1 protease inhibitors. In the inhibitory assays, the chemically synthesized [Ala67,95] HIV-1 protease was used. 相似文献