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991.
Hwang IW Ko DM Ahn TK Yoon ZS Kim D Peng X Aratani N Osuka A 《The journal of physical chemistry. B》2005,109(18):8643-8651
Intramolecular excitation energy hopping (EEH) time within a dodecameric porphyrin wheel C6ZA, in which six meso-meso linked zinc(II) diporphyrin (Z2) subunits are bridged by 1,3-phenylene spacers, is deduced by a F?rster energy hopping model based on S(1)-S(1) exciton-exciton annihilation and anisotropy depolarization. Under the assumption that the energy hopping sites are six Z2 subunits, two different observables (e.g., exciton-exciton annihilation and anisotropy depolarization times) consistently give the EEH time of 4.0 +/- 0.4 ps via 1,3-phenylene spacer of C6ZA, which is faster than 9.4 ps of linear 2Z2 (1,3-phenylene-linked zinc(II) tetraporphyrin). As a consequence, C6ZA serves as a well-defined two-dimensional model for a light-harvesting complex. 相似文献
992.
Kure B Ogo S Inoki D Nakai H Isobe K Fukuzumi S 《Journal of the American Chemical Society》2005,127(41):14366-14374
An open capsule-type octanuclear heterometallic sulfide cluster without an intramolecular inversion center [Ru(eta(6)-C(6)Me(6)){P(OMe)(3)}{MoO(mu(3)-S)(3)}(CuI)(2)](2) (5) has been synthesized for the first time by stepwise connection of three mononuclear building blocks, i.e., (i) [RuCl(2)(eta(6)-C(6)Me(6)){P(OMe)(3)}] (1a) as an octahedral terminal building block to control the direction of cluster expansion, (ii) [MoOS(3)](2)(-) as a tetrahedral polydentate building block owing to the strong coordination ability of the S atoms, and (iii) a CuI building block to form a trigonal planar (mu-S)(2)CuI unit or to form a linkage unit of two incomplete cubane-type octanuclear frameworks. The stepwise connection was made in the following order: [RuCl(2)(eta(6)-C(6)Me(6)){P(OMe)(3)}] (1a, mononuclear) --> [Ru(eta(6)-C(6)Me(6)){P(OMe)(3)}{MoOS(mu(2)-S)(2)}] (2a, dinuclear) --> [Ru(eta(6)-C(6)Me(6)){P(OMe)(3)}{MoO(mu(2)-S)(2)(mu(3)-S)}CuI] (3a, butterfly-type trinuclear) --> [Ru(eta(6)-C(6)Me(6)){P(OMe)(3)}{MoO(mu(3)-S)(3)}(CuI)(2)](2) (5). When P(OMe)(3) was replaced by P(OEt)(3), which is more bulky than P(OMe)(3), in the starting ruthenium building block [RuCl(2)(eta(6)-C(6)Me(6)){P(OEt)(3)}] (1b, mononuclear), only the tetranuclear incomplete single cubane cluster [Ru(eta(6)-C(6)Me(6)){P(OEt)(3)}{MoO(mu(3)-S)(3)}(CuI)(2)] (6) was generated, owing to the steric effect of P(OEt)(3). 相似文献
993.
This article introduces photochromic properties together with structures of organometallic compounds that undergo photo-induced structural rearrangement. The aim of this review is to survey the research on photochromism by using organometallics which possess by their own nature the properties responsible for the photochromism such as bonding and structural fluxionality, electronic state fluctuation, and photochemically active characteristic in both solution and the solid state. Therefore, the organometallics which include the well-characterized organic photochromic moieties, considered to be derivatives of such kinds of organic photochromic compounds, are excluded in this article. Mono-, di-, and poly-nuclear organometallic compounds are presented based on the reaction types such as linkage isomerization, haptotropic rearrangement, and reorganization of metal–ligand and/or metal–metal bonds. Very recently, the crystalline-state photochromism is becoming an attractive field of photochromic chemistry. As a demonstrative example, the photochromism of organometallic rhodium dinuclear complexes having a dithionite ligand (μ-O2SSO2), which shows 100% reversible interconversion in the crystalline-state and have been developed in the authors’ laboratory, will be discussed. 相似文献
994.
Chikashi Nakanishi Saori Ikeda Tetsuhiko Isobe Mamoru Senna 《Journal of Sol-Gel Science and Technology》2003,26(1-3):103-106
Silica fine particles in a single or sub-micrometer regime, containing FeCl3 and 2,2-bipyridine (bpy), were prepared by utilizing reverse micellar method. Formation of tris-bpy iron(II) ([Fe(bpy)3]2+) complex was induced in the silica fine particles by UV irradiation at 365 nm. The starting micellar solution was obtained by an injection of 0.04 cm3 HCl aqueous solution into 5 cm3 tetraethyl orthosilicate (TEOS)/cyclohexane (2 cm3/3 cm3) mixed solution containing 4–14 vol% of nonionic surfactant, polyoxyethylene(5) nonylphenyl ether (NP-5). Size of the silica particles was regulated by the concentration of NP-5. 相似文献
995.
Masataka Yamashita Dr. Daiki Kuzuhara Prof. Dr. Naoki Aratani Prof. Dr. Hiroko Yamada 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(21):6309-6314
A tetrathiafulvalene (TTF)‐conjugated bistetracene was synthesized and characterized in the molecular electronic structures based on the spectroscopic measurements and the single‐crystal X‐ray diffraction analysis. UV/Vis absorption and electrochemical measurements of 5 revealed the considerable electronic communication between two tetracenedithiole units by through‐bond and/or through‐space interactions. The difference in the crystal‐packing structures of 5 , showing polymorphism, results in a variety of intermolecular electronic‐coupling pattern. Of these, the π‐stacking structure of 5 A gave a large transfer integral of HOMOs (97 meV), which value is beyond hexacene and rubrene, thus, quite beneficial to achieve the high hole mobility. 相似文献
996.
A novel metal aquo‐ion affinity chromatography has been developed for the analysis of basic compounds using heat‐treated silica gel containing hydrated metal cations (metal aquo‐ions) as the packing material. The packing materials of the metal aquo‐ion affinity chromatography were prepared by the immobilization of a single metal component such as Fe(III), Al(III), Ag(I), and Ni(II) on silica gel followed by extensive heat treatment. The immobilized metals form aquo‐ions to present cation‐exchange ability for basic analytes and the cation‐exchange ability for basic analytes depends on pKa of the immobilized metal species. In the present study, to evaluate the retention characteristics of metal aquo‐ion affinity chromatography, the on‐line solid‐phase extraction of drugs was investigated. Obtained data clearly evidence the selective retention capability of metal aquo‐ion affinity chromatography for basic analytes with sufficient capacity. 相似文献
997.
998.
The first enantioselective synthesis of (3S,4aR,8aR)-1 (the enantiomer of natural okundoperoxide) has been accomplished. The synthesis features: 1) stereoselective installation of the peroxy functionality (16 → 17); 2) ring opening of peroxyacetal and subsequent intramolecular reaction between the hydroperoxide and the vinyl epoxide to form the peroxy six-membered ring (5 → 1). The absolute configuration of okundoperoxide was determined to be 3R,4aS,8aS by comparing specific rotations of the synthetic sample and the natural product. 相似文献
999.
Mitsuru Furuya Naoki Shimono Kazuyuki Yamazaki Ryota Domura Masami Okamoto 《Materials Today Chemistry》2017
To broaden the knowledge of cytotoxicity of natural rubber latex (NRL) nanoparticles we for the first time examined the latex biocompatibility in vitro against a panel of cancer cells (A549, A2780, and MDA-MB-231). Owing to fractionation of NRL nanoparticles by ultra-centrifuge, the effect of the non-rubber constituents (intermediate of 5.8 wt% and sediment of 0.2 wt%) on the cytotoxicity was clarified. For intermediate constituent, the half maximal inhibitory concentration (IC50) values at 24 h was 1.05 mg/mL for A549 cells, which was one order of magnitude higher in toxicity as compared to that for A2780 (0.24 mg/mL) and MDA-MB-231 (0.36 mg/mL) cells. In addition, profound studies including cell cycle arrest abilities and apoptosis induction profiles against cancer cells were discussed in detail. It was found that the constituents exhibit some significant effect on the cell cycle arrest and trigger apoptosis for A2780 cells. This effective apoptosis induction profiles was more prominent in MDA-MB-231 cells incubated with NRL nanoparticles and sediment loading conditions. The percentage of apoptotic cells was ca. 6–8% of the total cells. 相似文献
1000.