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111.
Yue Lu Koichi Nishio Shoichi Matsuda Yuki Toshima Hiroshi Ito Tomohiro Konno Kazuhiko Ishihara Souichiro Kato Kazuhito Hashimoto Shuji Nakanishi 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2014,126(8):2240-2243
There is growing awareness that circadian clocks are closely related to the intracellular redox state across a range of species. As the redox state is determined by the exchange of the redox species, electrochemically controlled extracellular electron transfer (EC‐EET), a process in which intracellular electrons are exchanged with extracellular electrodes, is a promising approach for the external regulation of circadian clocks. Herein, we discuss whether the circadian clock can be regulated by EC‐EET using the cyanobacterium Synechococcus elongatus PCC7942 as a model system. In vivo monitoring of chlorophyll fluorescence revealed that the redox state of the plastoquionone pool could be controlled with EC‐EET by simply changing the electrode potential. As a result, the endogenous circadian clock of S. elongatus cells was successfully entrained through periodically modulated EC‐EET by emulating the natural light/dark cycle, even under constant illumination conditions. This is the first example of regulating the biological clock by electrochemistry. 相似文献
112.
Kentaro Teramura Tomohiro Hosokawa Tai Ohuchi Tetsuya Shishido Tsunehiro Tanaka 《Chemical physics letters》2008,460(4-6):478-481
The photoluminescence spectrum and action spectrum for the photooxidation of orthovanadate-like (V=O)O3 species exhibiting photoluminescence at 520 nm indicate that the triplet excited state T1 of the orthovanadate-like species, which is formed from the singlet excited states S1 and S2 by intersystem crossing, is directly involved in the photooxidation of cyclohexane into cyclohexanone in the presence of molecular oxygen. 相似文献
113.
Yoshitane Imai Dr. Katuzo Murata Kakuhiro Kawaguchi Tomohiro Sato Nobuo Tajima Dr. Reiko Kuroda Dr. Yoshio Matsubara Dr. 《化学:亚洲杂志》2008,3(3):625-629
A solid‐state fluorescent host system was created by self‐assembly of a 21‐helical columnar organic fluorophore composed of (1R,2S)‐2‐amino‐1,2‐diphenylethanol and fluorescent 1‐pyrenecarboxylic acid. This host system has a characteristic 21‐helical columnar hydrogen‐ and ionic‐bonded network. Channel‐like cavities are formed by self‐assembly of this column, and various guest molecules can be included by tuning the packing of this column. Moreover, the solid‐state fluorescence of this host system can change according to the included guest molecules. This occurs because of the change in the relative arrangement of the pyrene rings as they adjust to the tuning of the packing of the shared 21‐helical column, according to the size of the included guest molecules. Therefore, this host system can recognize slight differences in molecular size and shape. 相似文献
114.
Igawa K Takada J Shimono T Tomooka K 《Journal of the American Chemical Society》2008,130(48):16132-16133
An enantioselective nucleophilic substitution reaction of achiral dialkoxysilane has been developed. The reaction proceeds with efficient stereocontrol on the silicon chirality center to give the enantioenriched silyl ether, which can be converted to the silanol without loss of enantiopurity. We have analyzed the steric course of the reaction by using DFT calculations and propose a transition state model to explain the observed enantioselectivity. 相似文献
115.
Tomohiro Seki Chi Feng Kentaro Kashiyama Shunichi Sakamoto Yuichi Takasaki Toshiyuki Sasaki Satoshi Takamizawa Hajime Ito 《Angewandte Chemie (International ed. in English)》2020,59(23):8839-8843
Ferroelasticity has been reported for several types of molecular crystals, which show mechanical‐stress‐induced shape change under twinning and/or spontaneous formation of strain. Aiming to create materials that exhibit both ferroelasticity and light‐emission characteristics, we discovered the first examples of ferroelastic luminescent organometallic crystals. Crystals of arylgold(I)(N‐heterocyclic carbene)(NHC) complexes bend upon exposure to anisotropic mechanical stress. X‐ray diffraction analyses and stress‐strain measurements on these ferroelastic crystals confirmed typical ferroelastic behavior, mechanical twinning, and the spontaneous build‐up of strain. A comparison with single‐crystal structures of related gold‐NHC complexes that do not show ferroelasticity shed light on the structural origins of the ferroelastic behavior. 相似文献
116.
Masaki Kondo Junichiro Kanazawa Tomohiro Ichikawa Takumi Shimokawa Yuki Nagashima Kazunori Miyamoto Masanobu Uchiyama 《Angewandte Chemie (International ed. in English)》2020,59(5):1970-1974
The silaboration of [1.1.1]propellane enables direct introduction of B and Si functional groups onto the bicyclo[1.1.1]pentane (BCP) scaffold in high yield under mild, additive‐free conditions. The silaborated BCP can be obtained on a gram‐scale in a single step without the need for column‐chromatographic purification, and is storable and easy to handle, providing a versatile synthetic intermediate for BCP derivatives. We also describe various conversions of the C?B/C?Si bonds on the BCP scaffold, including development of a modified Suzuki–Miyaura cross‐coupling reaction at the highly sterically hindered bridgehead sp3 carbon center of the BCP skeleton using a combination of highly activated BCP boronic esters, copper(I) oxide, and a PdCl2(dppf) catalyst system. 相似文献
117.
Tomohiro Ichitsuka Ikko Takahashi Nagatoshi Koumura Kazuhiko Sato Shū Kobayashi 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(37):16025-16030
Aryl amines are important pharmaceutical intermediates among other numerous applications. Herein, an environmentally benign route and novel approach to aryl amine synthesis using dehydrative amination of phenols with amines and styrene under continuous-flow conditions was developed. Inexpensive and readily available phenols were efficiently converted into the corresponding aryl amines, with small amounts of easily removable co-products (i.e., H2O and alkanes), in multistep continuous-flow reactors in the presence of heterogeneous Pd catalysts. The high product selectivity and functional-group tolerance of this method allowed aryl amines with diverse functional groups to be selectively obtained in high yields over a continuous operation time of one week. 相似文献
118.
Daisuke Saito Dr. Tomohiro Ogawa Dr. Masaki Yoshida Junichi Takayama Dr. Satoshi Hiura Prof. Dr. Akihiro Murayama Dr. Atsushi Kobayashi Prof. Dr. Masako Kato 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(42):18882-18889
A series of assembled PtII complexes comprising N-heterocyclic carbene and cyanide ligands was constructed using different substituent groups, [Pt(CN)2(R-impy)] (R-impyH+=1-alkyl-3-(2-pyridyl)-1H-imidazolium, R=Me ( Pt-Me ), Et ( Pt-Et ), iPr ( Pt- i Pr ), and tBu ( Pt- t Bu )). All the complexes exhibited highly efficient photoluminescence with an emission quantum yield of 0.51–0.81 in the solid state at room temperature, originating from the triplet metal-metal-to-ligand charge transfer (3MMLCT) state. Their emission colors cover the entire visible region from red for Pt-Me to blue for Pt- t Bu . Importantly, Pt- t Bu is the first example that exhibits blue 3MMLCT emission. The 3MMLCT emission was proved and characterized based on the temperature dependences of the crystal structures and emission properties. The wide-range color tuning of luminescence using the 3MMLCT emission presents a new strategy of superfine control of the emission color. 相似文献
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