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1.
D3h‐Symmetric Porphyrin‐Based Rigid Macrocyclic Ligands for Multicofacial Multinuclear Complexes in a One‐Nanometer‐Sized Cavity 下载免费PDF全文
Yohei Ohkoda Akane Asaishi Tomoya Namiki Tomoaki Hashimoto Midori Yamada Koichiro Shirai Yuta Katagami Dr. Tomoaki Sugaya Prof. Makoto Tadokoro Prof. Akiharu Satake 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(33):11745-11756
The one‐step synthesis of D3h‐symmetric cyclic porphyrin trimers 1 composed of three 2,2′‐[4,4′‐bis(methoxycarbonyl)]bipyridyl moieties and three porphyrinatozinc moieties was achieved from a nickel‐mediated reductive coupling of meso‐5,15‐bis(6‐chloro‐4‐methoxycarbonylpyrid‐2‐yl)porphyrinatozinc. Although cyclic trimers 1 were obtained as a mixture that included other cyclic and acyclic porphyrin oligomers, an extremely specific separation was observed only for cyclic trimers 1 when using columns of silica gel modified with pyrenylethyl, cyanopropyl, and other groups. Structural analysis of cyclic trimers 1 was carried out by means of NMR spectroscopy and X‐ray crystallography. Treatment of an η3‐allylpalladium complex with a cyclic trimer gave a tris(palladium) complex containing three η3‐allylpalladium groups inside the space, which indicated that the bipyridyl moieties inside the ring could work as bidentate metalloligands. 相似文献
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Kubra Eksiler Yoshito Andou Hidayah Ariffin Yoshihito Shirai 《Journal of polymer science. Part A, Polymer chemistry》2019,57(24):2575-2580
This study addresses the inherent issues surrounding surface modification methods of nanofibers and proposes an environmentally friendly and less toxic strategy for the surface modification of hydrophilic nanofiber. From the continuation of our previous work, which discussed the easy production of nanofiber (average size: 127 nm) from oil palm mesocarp fiber (OPMF), in this work, the surface of nanofibers (M‐IL‐OPMF) were modified through vapor‐phase‐assisted surface polymerization (VASP) to improve the affinity of interface between the polymer grafted M‐IL‐OPMF and non‐polar matrix. VASP of ε‐caprolactone was successfully proceeded from the [M‐IL‐OPMF] at 70 °C for 24 h and 72 h, and compositions were estimated to be 35.7% fiber/64.3% polymer and 27.8% fiber/72.2% polymer. To confirm the grafting of PCL, size‐exclusion chromatography (SEC) and Fourier transform infrared (FT‐IR) spectroscopy, thermogravimetry (TG), and dispersibility test in hydrophobic solvent were carried out. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 2575–2580 相似文献
5.
Shinpei Okawa Takeshi Hirasawa Ryota Sato Toshihiro Kushibiki Miya Ishihara Toshiharu Teranishi 《Optical Review》2018,25(3):365-374
Gold nanoparticles (AuNPs) are used as a contrast agent of the photoacoustic (PA) imaging. The efficiency of AuNPs has been discussed with the absorption cross section. However, the effects of the scattering of the light by AuNPs and surrounding medium on the PA signal from AuNPs have not been discussed. The PA signals from the aqueous solution of AuNPs were examined in the numerical simulation and the experiment. In the numerical simulation, the absorption and scattering cross sections of spherical and polyhedral AuNPs were calculated by Mie theory and discrete dipole approximation. Monte Carlo simulation calculated the absorbed light energy in the aqueous solution of AuNPs. Based on the PA wave equation, the PA signals were simulated. In the experiment, the PA signal from the aqueous solution of AuNP was measured by use of a piezoelectric film and a Q-switched Nd:YAG laser operated at 532 nm. The results of the numerical simulation and the experiment agreed well. In the numerical simulation and the experiment, a single Au nanocube with 50-nm edge generated the peak value of the PA signal significantly. It was approximately 350 times and twice as large as the peak values of the spherical AuNPs with 10- and 50-nm diameters, respectively. The peak value of the PA signal depended on both the absorption and scattering coefficients of the AuNPs and the surrounding medium. The peak value increased with the scattering coefficient in a quadratic manner. The character of the temporal profile of the PA signal such as full width at half maximum depended on the scattering coefficient of the AuNPs. 相似文献
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Pentacyanoferrate-bound poly(1-vinylimidazole) (PVI[Fe(CN)5]) was selected as a mediator for amperometric creatinine determination based on the reductive H2O2 detection. Creatinine amidohydrolase (CNH), creatine amidohydrolase (CRH), sarcosine oxidase (SOD), peroxidase (POD), and PVI[Fe(CN)5] were crosslinked with poly(ethylene glycol) diglycidyl ether (PEGDGE) on a glassy carbon (GC) electrode for a creatinine biosensor fabrication. Reduction current was monitored at −0.1 V in the presence of creatinine and O2. It is revealed that PVI[Fe(CN)5] is suitable as a mediator for a bioelectrocatalytic reaction of POD, since PVI[Fe(CN)5] neither reacts with reactants nor works as an electron acceptor of SOD. The amounts of PVI[Fe(CN)5], PEGDGE, and enzymes were optimized toward creatinine detection. Nafion as a protecting film successfully prevented the enzyme layer from interferences. The detection limit and linear range in creatinine determination were 12 μM and 12–500 μM (R2 = 0.993), respectively, and the sensitivity was 11 mA cm−2 M−1, which is applicable for urine creatinine tests. The results of the creatinine determination for four urine samples measured with this proposed method were compared with Jaffe method, and a good correlation was obtained between the results. 相似文献
8.
Generation of Aryl(2‐lithiophenyl)methanone O‐Methyl Oximes and Their Use for the Synthesis of N‐(3‐Alkyl‐1‐aryl‐ or 1,3‐diaryl‐1H‐isoindol‐1‐yl)‐O‐methylhydroxylamines via the Reaction with Nitriles 下载免费PDF全文
Kazuhiro Kobayashi Kota Matsumoto Yuu Shirai Hiroaki Ishikawa Hiroki Inouchi Miyuki Tanmatsu 《Helvetica chimica acta》2014,97(7):915-922
An efficient two‐step procedure for the preparation of a new type of 1H‐isoindoles, i.e., N‐(3‐alkyl‐1‐aryl‐ or 1,3‐diaryl‐1H‐isoindol‐1‐yl)‐O‐methylhydroxylamines 5 , from readily available aryl(2‐bromophenyl)methanones 1 has been developed. Aryl(2‐bromophenyl)methanone O‐methyloximes 2 , derived from the corresponding ketones, were treated with BuLi in Et2O at 0° to generate novel lithium compounds, aryl(2‐lithiophenyl)methanone O‐methyloximes 3 , which were allowed to react with nitriles to give the desired products 5 in moderate‐to‐fair yields. 相似文献
9.
Sayoko Nagashima Shota Furukawa Satoshi Kamiguchi Ryu Kajio Hiroshi Nagashima Aritomo Yamaguchi Masayuki Shirai Hideki Kurokawa Teiji Chihara 《Journal of Cluster Science》2014,25(5):1203-1224
A series of molecular rhenium sulfide clusters [Re6S8(OH)6?n (H2O) n ](4?n)? (n = 0, 2, 4, 6) catalyze dehydrogenation of alcohols, and hydrogenation of ketones and olefins in a hydrogen stream at 350 °C. The catalytic activities of the dianionic and neutral clusters (n = 2, 4) are lower than those of tetraanionic and dicationic clusters (n = 0, 6) for all the reactions. When 1,4-butanediol is allowed to react over K4[Re6S8(OH)6], dehydrogenation proceeds to yield 2-hydroxytetrahydrofuran and successively γ-butyrolactone above 300 °C. Over [Re6S8(H2O)6]SO4 dehydration proceeds to yield tetrahydrofuran above 250 °C. The thermal activation mechanisms of these clusters were studied by powder X-ray diffraction analyses, Raman spectrometry, extended X-ray absorption fine structure spectrometry, thermogravimetry, and differential thermal analyses. The catalytically active site of K4[Re6S8(OH)6] is an uncoordinated metal site (Lewis acid site) developed by the loss of a water molecule from two hydroxo ligands. The active site of [Re6S8(H2O)6]SO4 is a Brønsted acid site; the anhydrous aqua cluster dication disproportionates to a hydroxo cluster monocation and a proton. Both of the octahedral cluster frameworks are retained up to 500 °C. 相似文献
10.
Fluorescence correlation spectroscopy (FCS) of colloidal nanoparticles using a near-field fiber probe was numerically simulated.
The near-wall dynamics was simulated by accounting for the anisotropic mobility of nanoparticles owing to hydrodynamic interaction
with a wall (Stokes viscous force). By comparing the simulation results with theoretical model calculations, we found that
the influence of anisotropic diffusion is insignificant in near-field FCS autocorrelation analysis. 相似文献