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991.
Uchiyama D Oikawa H Otomo K Nango M Dewa T Fujiyoshi S Matsushita M 《Physical chemistry chemical physics : PCCP》2011,13(24):11615-11619
As a model of photosynthetic unit (PSU), self-assembled aggregates of pigment-protein complexes from photosynthetic bacteria were prepared in a lipid bilayer by reconstitution of the light-harvesting 2 (LH2) complex and light-harvesting 1-reaction center (LH1-RC) complex through detergent removal of their micelles in the presence of lipids. By performing polarization-controlled fluorescence and fluorescence-excitation spectroscopy on single aggregates at a temperature of 5 K, the composition of individual aggregates was determined and excitation energy transfer (EET) between constituent complexes was observed. LH2 and LH1-RC from a bacterium, Rhodobacter (Rb.) sphaeroides, were found to form a trimeric aggregate in which EET takes place from one LH2 to two LH1-RCs. In contrast, a heterodimer of LH2 and LH1-RC in which EET works was found to assemble from a combination of complexes of different bacterial species, that is, LH2 from Rb. sphaeroides and LH1-RC from Rhodopseudomonas (Rps.) palustris. 相似文献
992.
This article reviews new information about polymorphic structures, kinetic and microscopic properties of fat crystals in colloidal dispersion states such as aggregates (spherulite), oil-in-water (O/W) emulsion and water-in-oil (W/O) emulsion. The kinetic processes of fat crystallization under external factors such as different cooling rates, shear and ultrasound irradiation are reviewed. Microstructures of fats revealed by synchrotron radiation microbeam X-ray diffraction techniques in bulk and emulsion states are also reviewed for the first time. 相似文献
993.
Hiroto S Suzuki K Kamiya H Shinokubo H 《Chemical communications (Cambridge, England)》2011,47(25):7149-7151
The synthesis of a variety of diarylethenes through the Suzuki-Miyaura coupling reaction of 1,2-dichlorohexafluorocyclopentene with arylboronic acids and esters has been developed. Thiophenes with various substituents such as cyano and ester functionalities can be incorporated. 相似文献
994.
New π-conjugated trinuclear dithiolenes with group 8 (6, Ru(II)) and 10 (7 and 8, Ni(II) and Pt(II)) metals were synthesized. Compounds 6 and 7 exhibited intense electronic communication through the phenylene bridge among the three dithiolene moieties during oxidation of the metalladithiolene rings, which has not been confirmed in the analogous family of group 9 metals, 1-5. Compound 8 exhibited an intense absorption band across the visible and near-IR regions, which was assigned as a charge transfer to the diimine and was red-shifted and broadened compared to the corresponding band of the mononuclear complex. 相似文献
995.
Satoru Kageyama Satoshi Seino Takashi Nakagawa Hiroaki Nitani Koji Ueno Hideo Daimon Takao A. Yamamoto 《Journal of nanoparticle research》2011,13(10):5275-5287
PtRu nanoparticle catalysts with 2-nm size supported on carbon were synthesized by a radiolytic process, assisted with the
addition of dl-tartaric acid. Gradual alloying with the addition was confirmed by structural analyses with techniques of the X-ray diffraction
and the X-ray absorption fine structure. Their methanol oxidation activities evaluated by the linear sweep voltammetry were
higher than that of the commercial one, and found to be enhanced in accordance with the gradual change in the bimetallic structure
from the Pt-core/Ru-shell to the random alloy. A good correlation was found between the catalytic activity and the indicators,
which stands for the occurring frequency of the Pt–Ru bonds, calculated from the coordination numbers determined by the extended
X-ray absorption fine structure analysis. It was confirmed that the addition of dl-tartaric acid in the radiolytic process certainly promoted the random alloy formation of PtRu bimetallic nanoparticles and
enhanced their methanol oxidation activity. 相似文献
996.
Ravinder S Reddy Satoru Iguchi Shoji Kobayashi Masahiro Hirama 《Tetrahedron letters》1996,37(52):9335-9336
Coupling of functionalized cyclopentenyl iodides with ethynyl oxiranes has been achieved by using catalytic amount of Pd(CH3CN)2Cl2 and CuI in the presence of i-Pr2NEt in moderate to good yields. 相似文献
997.
998.
Kiyoshi Tanaka Makoto Deguchi Satoru Yamaguchi Kouji Yamada Satoru Iwata 《Journal of heterocyclic chemistry》2001,38(1):131-136
2‐(3,4,5,6‐Tetrafluoro‐2‐hydroxyphenyl)benzoxazole ( 2 ) emits the long wavelength fluorescence around 500 nm in nonpolar solvent via the intramolecular proton transfer process in the excited state of 2 (enol‐form) and also emits the intermediate wavelength fluorescence around 440 nm in polar solvent, which is assumed to originate from the excited state of 2 (anion). The ease of formation of 2 (anion), compared to 2‐(2‐hydroxyphenyl)benzoxazole ( 1 ), is explained by the strongly inductive fluorine atoms. In a solvent with the intermediate polarity, 2 emits both fluorescences and their relative intensity is dependent on the concentration of 2 , which is supposed to be caused by the high sensitivity of the intermediate wavelength emission to the concentration quenching. 相似文献
999.
Satoru Hiroto Naoki Aratani Dr. Naoki Shibata Prof. Dr. Yoshiki Higuchi Prof. Dr. Takahiro Sasamori Dr. Norihiro Tokitoh Prof. Dr. Hiroshi Shinokubo Prof. Dr. Atsuhiro Osuka Prof. Dr. 《Angewandte Chemie (International ed. in English)》2009,48(13):2388-2390
Pyridine attacks : Nucleophilic addition of pyridine derivatives to a doubly linked corrole, which is a stable singlet biradical species, occurs at the bay area with high regioselectivity to provide zwitterionic dimers (see picture; Ar=C6F5). Charge transfer between the anionic corrole and the pyridinium groups induces effective fluorescence quenching of the corrole dimer, which can be utilized for selective fluoride ion recognition.
1000.
Hayashi K Sushko PV Ramo DM Shluger AL Watauchi S Tanaka I Matsuishi S Hirano M Hosono H 《The journal of physical chemistry. B》2007,111(8):1946-1956
A novel nanoporous material 12CaO.7Al2O3 (C12A7) offers a possibility of incorporating large concentrations (>1021 cm-3) of a wide range of extraframework anions inside its nanopores. We have investigated, both experimentally and theoretically, optical absorption associated with several types of such anions, including F-, OH-, O-, O2-, O2-, and O22-, and assigned their optical absorption bands. It is demonstrated that the chemical identity and concentration of extraframework anions can be controlled by an appropriate treatment of "as grown" C12A7. We also show that the position of the adsorption edge is, in turn, determined by the chemical identity of the extraframework species and can be varied in the range of approximately 4-6 eV. We suggest that C12A7 is a unique host material, which can be used as a playground for studying negatively charged species that are unstable in other environments. 相似文献