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141.
Bigi JP Harman WH Lassalle-Kaiser B Robles DM Stich TA Yano J Britt RD Chang CJ 《Journal of the American Chemical Society》2012,134(3):1536-1542
We report the generation and characterization of a new high-spin iron(IV)-oxo complex supported by a trigonal nonheme pyrrolide platform. Oxygen-atom transfer to [(tpa(Mes))Fe(II)](-) (tpa(Ar) = tris(5-arylpyrrol-2-ylmethyl)amine) in acetonitrile solution affords the Fe(III)-alkoxide product [(tpa(Mes2MesO))Fe(III)](-) resulting from intramolecular C-H oxidation with no observable ferryl intermediates. In contrast, treatment of the phenyl derivative [(tpa(Ph))Fe(II)](-) with trimethylamine N-oxide in acetonitrile solution produces the iron(IV)-oxo complex [(tpa(Ph))Fe(IV)(O)](-) that has been characterized by a suite of techniques, including mass spectrometry as well as UV-vis, FTIR, M?ssbauer, XAS, and parallel-mode EPR spectroscopies. Mass spectral, FTIR, and optical absorption studies provide signatures for the iron-oxo chromophore, and M?ssbauer and XAS measurements establish the presence of an Fe(IV) center. Moreover, the Fe(IV)-oxo species gives parallel-mode EPR features indicative of a high-spin, S = 2 system. Preliminary reactivity studies show that the high-spin ferryl tpa(Ph) complex is capable of mediating intermolecular C-H oxidation as well as oxygen-atom transfer chemistry. 相似文献
142.
Maria Chiara Munisso Satomi Yano Wenliang Zhu Giuseppe Pezzotti 《Continuum Mechanics and Thermodynamics》2008,20(3):123-132
The main aim of this work is a precise experimental assessment of the local stress fields developed at the notch-root in a
ruby crystal, selected as a paradigm brittle material, by means of photo- and electron-stimulated luminescence techniques.
Our approach takes advantage of the piezo-spectroscopic (PS) effect, which consists of a spectral shift of the luminescence
emitted by the material due to lattice strain. Highly spatially resolved stress maps were extensively collected at the notch-root
and spectral shifts monitored for the chromophoric (R-lines) fluorescence observed in a single-crystalline ruby sample. Experimental data were analyzed and compared to the theoretical
solutions of notch-root stress fields given by Filippi and by Creager-Paris. Due to its inherent simplifications, the Creager–Paris
solution was found leading to underestimation of the maximum stress value piled up in the material, while the Filippi’s solution
represented a more suitable approximation for the stress field developed at the notch-root. 相似文献
143.
K. Yano 《SAR and QSAR in environmental research》2013,24(1):15-26
Abstract A method for a preliminary survey of the relationship between molecular structure and performance was described using 1506 random data of structure-acute toxicity for mice (intravenously dosed). The structural patterns of the weakest toxic structures (111) were extracted from the data and the patterns discriminated for 64.2% of the other structures (1395). As for the 826 structures of strongest toxicity, 78.3% were discriminated by these structural patterns. These results were obtained by using structural parameter ratios to describe the structural patterns and the exhaustive elimination process to select the best parameter ratio from many candidates. The results were summarized in the form of a chart which can be used for practical screening for the weakest toxic structures. 相似文献
144.
Makoto Obata Noriko Matsuura Kazunori Mitsuo Hiroki Nagai Keisuke Asai Masafumi Harada Shiho Hirohara Masao Tanihara Shigenobu Yano 《Journal of polymer science. Part A, Polymer chemistry》2010,48(3):663-670
A novel methacrylate monomer bearing 5,10,15,20‐tetraphenylporphyrinato palladium(II) (PdTPP) (monomer 1a ) was synthesized and copolymerized with isobutyl methacrylate (IBM) and 2,2,2‐trifluoroethyl methacrylate (TFEM) to give poly (IBM‐co‐TFEM) bearing PdTPP (copolymer 2a ) as a dye‐conjugated oxygen‐permeable polymer for pressure‐sensitive paint applications. The introduction of PdTPP into copolymer 2a was confirmed by UV–vis spectroscopy and extended X‐ray absorption fine structure analysis. The Stern–Volmer plots of the copolymer 2a and a mixture of PdTPP and poly(IBM‐co‐TFEM) both showed downward curvature, unlike that of the platinum complex analogue (copolymer 2b ) previously reported. The plots were successfully fitted with a two‐site model to give two distinct Stern–Volmer constants (KSV1 and KSV2) and the partition ratio f1. Interestingly, the f1 values for the copolymer 2a were almost constant at about 0.98, whereas those of the mixture of PdTPP and poly(IBM‐co‐TFEM) increased from 0.889 to 0.967 as the temperature was increased. This finding suggests that there are two distinct microheterogeneities, one temperature‐dependent and the other temperature‐independent, in the mixture of PdTPP and poly(IBM‐co‐TFEM). The dye‐conjugation approach effectively eliminates the temperature‐dependent, but not the temperature‐independent microheterogeneity. The luminescence decays of copolymers 2a and 2b and the corresponding mixtures in the absence of oxygen indicated that the temperature‐dependent microheterogeneity involves an oxygen diffusion process, whereas the temperature‐independent one appears to be inherent nature in PdTPP. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 663–670, 2010 相似文献
145.
146.
147.
Masafumi Yano Yutaka Ishida Kazunobu Sato Munetaka Oyama 《Journal of Physics and Chemistry of Solids》2004,65(4):733-736
A series of N,N,N′,N′-tetraaryl-1,3-phenylenediamines with various substituents at the para-position of peripheral rings were designed and synthesized. Electrochemical and novel electron transfer stopped-flow methods were invoked for characterizing the absorption spectra of the corresponding short-lived mono- and dicationic states. Both thermodynamic and kinetic stabilization are required to extend the lifetime of the dicationic states. Useful molecular design rules for stabilizing the dicationic states of N,N,N′,N′-tetraaryl-1,3-phenylenediamines as precursors for positively charged high-spin systems were elucidated. 相似文献
148.
Carboxymethylcellulose (CMC) is well known as a safe and biodegradable material, which is widely used as food additives, wash paste, etc., in our daily life. Aiming at the environmental purification of this eco-friendly substance, the authors have investigated Cu2+ absorption property of CMC gel that was crosslinked by irradiating with γ-rays without toxic crosslinker. The CMC gel has revealed to capture Cu2+ of which number depends on the γ-ray dose as well as the CMC concentration, indicating the chelation by carboxyl group at the end of the side chain. 相似文献
149.
150.
Satoka Aoyagi Akira Yano Yasutaka Yanagida Eiji Tanihira Akio Tagawa Mitsuo Iimoto 《Chemical physics》2006
This study investigated the control of dissolved oxygen concentration using magnetic forces from gradient magnetic fields near a Nd–Fe–B permanent magnet. Maximum values of magnetic flux density and the product of the magnetic flux density and its gradient were 0.63 T and 44 T2/m, respectively. The magnet was placed under a Petri dish filled with 15 ml of 10% ammonia water. The Petri dish had a copper sheet in the center. Absorbance of tetraamminecopper(II) complex produced by the reaction in oxygen was measured using a spectrophotometer to observe oxygen concentration. Results showed that the magnetic field quantitatively enhanced tetraamminecopper(II) complex production. Moreover, remarkable enhancement of the copper complex production occurred in the magnetic field at less than 2 mm depth. The calculated magnetic force increase near the magnet surface supports this result. These results show that greater enhancement of the reaction rate occurs when the stronger magnetic force acts on oxygen molecules. 相似文献