meta-Ethynylpyridine 18-mer associates with octyl β-D-glucopyranoside to show an induced circular dichroism (CD) band at around 337 nm in CH(2)Cl(2). The addition of copper(II) triflate and o-phenanthroline enhanced the CD band. Even when an equimolar amount of β-L-glucopyranoside was added to make the system racemic, the CD was memorized and remained for several weeks. 相似文献
Anion-controlled circular dichroism (CD) spectral changes in Hg(2+) complexes with a chiral bidentate ligand are reported. Although the Hg(CF(3)SO(3))(2) and Hg(CF(3)CO(2))(2) complexes with (R)-(-)-1-(naphthalen-1-yl)-N,N-bis(pyridin-4-ylmethyl)ethanamine, (R)-(-)-1, show significant CD spectral changes, no CD spectral changes were observed in the HgCl(2), HgBr(2), Hg(CN)(2), or Hg(CH(3)CO(2))(2) complexes. X-ray analysis indicates that both the (R)-(-)-1-Hg(CF(3)SO(3))(2) and (R)-(-)-1-HgCl(2) complexes form a coordination polymer and a discrete 2:3 [=(R)-(-)-1/HgCl(2)] complex with a figure-eight structure. X-ray crystallography revealed that (i) the Hg-Hg distances bridged by anions vary depending on the anions used and (ii) a coordination polymer cannot be formed when the Hg-Hg distances are too short. Therefore, the formation of a coordination polymer is required to give the observed significant CD spectral changes. 相似文献
Direct photoelectrochemical conversion of toluene (TL) to methylcyclohexane (MC) with water has been examined as an organic hydride conversion using light irradiation. The production of MC from TL was observed on Pt/CdS/Cu(2)ZnSnS(4)/Mo photoelectrodes with anion-type ionomer membrane assemblies. A cathodic photocurrent was observed below 0.7 V vs RHE (V(RHE)) in 0.1 M Na(2)SO(4)/NaOH (pH 9.5) aqueous solution, and an apparent photocurrent density of 0.5 mA cm(-2) was obtained at 0 V(RHE) under the irradiation of a 300 W Xe lamp with a 420 nm cutoff filter. The yield of MC was measured by gas chromatography, and an 88% faradaic efficiency was estimated. This study suggests the possibility of direct energy conversion from solar energy to MC as an energy carrier of organic hydrides. 相似文献
We have observed secondary particles and photons emitted from hydrogen terminated Si(1 1 1) 1 × 1 surfaces in the interactions with highly charged ions (HCIs) of iodine having a wide range of charge state, q, from I17+ up to I53+, fully stripped iodine ion. A TOF-SIMS (time-of-flight secondary ion mass spectrometry) apparatus has been used to investigate secondary emissions where protons are dominant signals in the TOF spectra. Measured yields of H+ and show strong q-dependences, proportional to q3.4 and q5, respectively. For Si+, while the yield remains constant for q < ∼ 25, it begins increasing with q1.4 at higher q (∼25). The mechanism of secondary emissions is briefly discussed. 相似文献
Efficient oxidative transformation of thiols to disulfides took place in the presence of activated carbon under an oxygen (or air) atmosphere. The present oxidation method is available not only for a variety of thiols such as simple aromatic and aliphatic thiols but also for 3,4-dihydropyrimidin-2(1H)-thiones and N-Boc-l-cysteine. 相似文献
The reaction of N-(3-phenylpropionyloxy)phthalimide (1a) and N-tosyloxy (5a,b) derivatives with nucleophiles was examined and found to give the products via Lossen-type rearrangement. In order to obtain the scope of this reaction mechanism, further studies the reaction of several N-sulfonyloxyimide derivatives with various nucleophiles under similar conditions were carried out and found to afford the corresponding same types of products in high yields. 相似文献
To the limit : Electrolyte flow accelerates the mass‐transfer process in a droplet cell (see picture). The limiting current in the cell is expressed as a sum of hydrodynamic and stagnant terms. The current derived from the latter term indicates that convective mass transfer in the cell would be changed dramatically at a significantly small volumetric flow rate.
Consider the N-person non-cooperative game in which each player’s cost function and the opponents’ strategies are uncertain. For such an
incomplete information game, the new solution concept called a robust Nash equilibrium has attracted much attention over the
past several years. The robust Nash equilibrium results from each player’s decision-making based on the robust optimization
policy. In this paper, we focus on the robust Nash equilibrium problem in which each player’s cost function is quadratic,
and the uncertainty sets for the opponents’ strategies and the cost matrices are represented by means of Euclidean and Frobenius
norms, respectively. Then, we show that the robust Nash equilibrium problem can be reformulated as a semidefinite complementarity
problem (SDCP), by utilizing the semidefinite programming (SDP) reformulation technique in robust optimization. We also give
some numerical example to illustrate the behavior of robust Nash equilibria. 相似文献
Preparation of p-type hydrogenated microcrystalline silicon oxide thin films (p-μc-Si1−xOx:H) by 13.56 MHz RF-PECVD method for use as a p-layer of hetero-junction μc-Si:H solar cells is presented. We investigated effects of wide-gap p-μc-Si1−xOx:H layer on the performance of hetero-junction μc-Si:H solar cells under various light intensity. We observed that a wide-gap p-μc-Si1−xOx:H was effective in improving the open-circuit voltage (Voc) of the solar cells. We also confirmed that the Voc logarithmically increased with increasing light intensity, and the enhancement of Voc became larger with increasing band gap of p-layer. These results indicate that wide-gap p-μc-Si1−xOx:H is a promising material for use as window layer in hetero-junction μc-Si:H solar cells. 相似文献
Thermal isomerization of cyclobutaphenanthrene to o-quinodimethane was investigated. Sterically congested substituents or electron-donating substituents on the four-membered ring promoted the ring-opening, affording o-quinodimethane in a relatively stable form. Isolation of the newly prepared o-quinodimethane allowed its structural elucidation and investigation of its potential reactivities. Dual [4+2] cycloaddition of an aryne and o-quinodimethane afforded tetrabenzopentacene, demonstrating the synthetic application of the isolated compound. 相似文献