Aryl‐substituted 1,1,4,4‐tetracyano‐1,3‐butadienes (FcTCBDs) and bis(1,1,4,4‐tetracyanobutadiene)s (bis‐FcTCBDs), possessing a ferrocenyl group on each terminal, were prepared by the reaction of a variety of alkynes with tetracyanoethylene (TCNE) in a [2+2] cycloaddition reaction, followed by retro‐electrocyclization of the initially formed [2+2] cycloadducts (i.e., cyclobutene derivatives). The characteristic intramolecular charge transfer (ICT) between the donor (ferrocene) and acceptor (TCBD) moieties were investigated by using UV/Vis spectroscopy. The redox behaviors of FcTCBDs and bis‐FcTCBDs were examined by cyclic voltammetry (CV) and differential pulse voltammetry (DPV), which revealed their properties of multi‐electron transfer depending on the number of ferrocene and TCBD moieties. Moreover, significant color changes were observed by visible spectroscopy under the electrochemical reduction conditions. 相似文献
The asymmetric Michael addition of 2-alkoxyphenyl α-substituted nitroacetates to non-prochiral α,β-unsaturated carbonyl compounds catalyzed by 10 mol % of sodium 2′-[2-(2-methoxyethoxy)ethoxy]-1,1′-binaphthalen-2-oxide gave the desired adducts in high yields with up to 95% ee. 相似文献
Microdevices designed for practical environmental pollution monitoring need to detect specific pollutants such as dioxins. Bisphenol A (BPA) has been widely used as a monomer for the synthesis of polycarbonate and epoxy resins. However, the recent discovery of its high potential ability to disrupt human endocrine systems has made the development of smart systems and microdevices for its detection and removal necessary. Molecule‐responsive microsized hydrogels with β‐cycrodextrin (β‐CD) as ligands are prepared by photopolymerization using a fluorescence microscope. The molecule‐responsive micro‐hydrogels show ultra‐quick shrinkage in response to target BPA. Furthermore, the flow rate of a microchannel is autonomously regulated by the molecule‐responsive shrinking of their hydrogels as smart microvalves.
Summary A new method for the determination of association constants by the measurement of chronopotentiometric transition time has been developed and applied to the study on the outer-sphere association of some substitution-inert complex cations with sulphate ions. The association constants were determined from the change in transition time as function of the concentration of sulphate ions at ionic strength 0.1 (NaClO4) and 25° C: 93 ±8 for [Co(NH3)6]3+SO42–, 99 ±15 for [Co(en)3]3+SO42–, 61 ±7 for [Cr(NH3)6]3+SO42– and 58 ±8 for [Cr(en)3]3+SO42–. The ratios of the diffusion coefficients of the univalent ion-pairs and tervalent substitution-inert complex cations were also obtained. From these ratios the diffusion coefficients of the univalent ion-pairs were calculated, which were found to differ not greatly from those of univalent complex ions with similar structures.
Zusammenfassung Eine neue Methode zur Bestimmung von Assoziationskonstanten aus den Transitionszeiten chronopotentiometrischer Messungen wurde entwickelt. Sie wurde zur Untersuchung der Assoziation von Sulfationen in zweiter Sphäre an koordinativ abgesättigten Komplex-Kationen herangezogen. Die Assoziationskonstanten wurden aus der Abhängigkeit der Transitionszeit von der Sulfatkonzentration in Medien der Ionenstärke 0,1 (NaClO4) und bei 25° C bestimmt. Man erhält folgende Werte: 93±8 für [Co(NH3)6]3+SO42–, 99±15 für [Co(en)3]3+SO42–, 61±7 für [Cr(NH3)6]3+SO42– und 58±8 für [Cr(en)3]3+SO42–. Die Verhältnisse der Diffusionskoeffizienten der einwertigen Ionenpaare zu denen der dreiwertigen Komplex-Kationen wurden ebenfalls bestimmt. Aus diesen Verhältnissen lassen sich die Diffusionskoeffizienten der Ionenpaare berechnen. Man erhält eine gute Übereinstimmung mit den Werten für einwertige Komplexionen mit ähnlicher Struktur.
Dedicated to Prof. Dr. M. von Stackelberg on his 70th birthday. 相似文献
For the treatment of patients with cancer of the thoracic esophagus, lymphatic spreading is one important factor to infer how advanced their cancer is. We introduced a one-dimensional scale based on lymphatic spreading patterns, the stage of cancer, to express how advanced their cancer is, and we proposed a method to infer each patient's stage from his lymphatic spreading pattern by applying a Bayesian model. Our Bayesian model was built based on the assumption that lymphatic spreading in cancer could be explained as what was brought about by the advance of stage. In the modeling, we introduced the probability of what stage each patient was in as a prior distribution. We also introduced distribution functions of Weibull distributions to express the relation between the advance of stage and the increase of the probability of metastasis. Our model was applied to the data of nodal involvement obtained from 103 patients with cancer of the thoracic esophagus and the parameters were estimated with the maximum likelihood method. AIC was used to check that the data had enough information to be divided into the stages of a clinically reasonable number. With the estimated parameters, we inferred the probability of metastasis to each lymph node in each stage and calculated by Bayes' theorem with 31 new patients the probability of what stage they were in. The results well represented some characteristics of the lymphatic spreading and suggested the appropriateness of our approach.The present study was carried out under the ISM Cooperative Research Program (91-ISM·CRP-18). 相似文献
Simultaneous measurements of the electrical resistance and X-ray diffraction under pressure have revealed that ZnTe exhibits two subsequent structural transitions at approximately 85 and 130 kbar, accompanied by a conspicuous rise and drop in the resistance, respectively. 相似文献
Corrective matrix that is derived to restore consistency of discretization schemes can significantly enhance accuracy for the inside particles in the Moving Particle Semi‐implicit method. In this situation, the error due to free surface and wall boundaries becomes dominant. Based on the recent study on Neumann boundary condition (Matsunaga et al, CMAME, 2020), the corrective matrix schemes in MPS are generalized to straightforwardly and accurately impose Neumann boundary condition. However, the new schemes can still easily trigger instability at free surface because of the biased error caused by the incomplete/biased neighbor support. Therefore, the existing stable schemes based on virtual particles and conservative gradient models are applied to free surface and nearby particles to produce a stable transitional layer at free surface. The new corrective matrix schemes are only applied to the particles under the stable transitional layer for improving the wall boundary conditions. Three numerical examples of free surface flows demonstrate that the proposed method can help to reduce the pressure/velocity fluctuations and hence enhance accuracy further. 相似文献
Burning velocity measurements of six types of fluoropropanes including structural isomers were carried out in order to understand the flammability of hydrofluorocarbons (HFC). The burning velocity (Su) was determined by applying a spherical flame model to the pressure rise during combustion, which was measured at room temperature and at initial pressures of 80-107 kPa over a wide range of HFC/air concentrations. The maximum Su of 1-fluoropropane (HFC-281fa), 2-fluoropropane (HFC-281ea), 1,3-difluoropropane (HFC-272fa), 2,2-difluoropropane (HFC-272ca), 1,2,3-trifluoropropane (HFC-263ea), and 1,1,1-trifluoropropane (HFC-263fb) was 35.0, 31.8, 31.9, 21.2, 25.7, and 14.5 cm s−1, respectively. Note that the maximum Su of HFC-263ea was appreciably higher than that of HFC-272ca, which shows the importance of the F-atom distribution, as well as of the F/H ratio in the HFC molecule. The results of equilibrium calculation for these HFCs showed that Su is positively correlated with the flame temperature and the concentrations of the active chain carriers H and OH in the flame. We conducted a trial to interpret the magnitude of Su by means of the effects of substituents for C1-C3 HFCs. As a result, it has been found that the order of inhibition efficiency for Su decreases in the order of CF3 > CF2 > CF. 相似文献
The first electronic transition (?←X?) of liquid water was studied from the perspective of the hydration of cations by analyzing the attenuated total reflection far-ultraviolet (ATR-FUV) spectra of the Group I, II, and XIII metal nitrate electrolyte solutions. The ?←X? transition energies of 1 M electrolyte solutions are higher (Li(+): 8.024 eV and Cs(+): 8.013 eV) than that of pure water (8.010 eV) and linearly correlate with the Gibbs energies of hydration of the cations. The increases in the ?←X? transition energies are mostly attributable to the hydrogen bond formation energies of water molecules in the ground state induced by the presence of the cations. The deviation from the linear relation was observed for the high charge density cations, H(+), Li(+), and Be(2+), which reflects that the electronic energies in the excited states are also perturbed. Quantum chemical calculations show that the ?←X? transition energies of the water-cation complexes depend on the hydration structures of the cations. The calculated ?←X? transition energies of the water molecules hydrating high charge density cations spread more widely than those of the low charge density cations. The calculated transition energy spreads of the water-cation complexes directly correlate with the widths of the ?←X? transition bands measured by ATR-FUV spectroscopy. 相似文献