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31.
Herein, we report the fabrication of a sensitive ratiometric and colorimetric luminescent thermometer with a wide operating‐temperature range, from cryogenic temperatures up to high temperatures, through the combination of lanthanide and transition metal complexes. Benefiting from the transition metal complex as a self‐reference, the lanthanide content in the mixed‐coordination complex, Eu0.05(Mebip‐mim bromine)0.15Zn0.95(Mebip‐mim bromine)1.9, was lowered to 5 %. 相似文献
32.
Peter Herich Marek Fronc Jozef Koíek 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(2):159-164
Three new complexes with 3,6‐dichlorobenzene‐1,2‐dithiol (bdtCl2), namely methyltriphenylphosphonium bis(3,6‐dichlorobenzene‐1,2‐dithiolato‐κ2S,S′)cobaltate(1−), (C19H18P)[Co(C6H2Cl2S2)2], (I), bis(methyltriphenylphosphonium) bis(3,6‐dichlorobenzene‐1,2‐dithiolato‐κ2S,S′)cuprate(2−) dimethyl sulfoxide disolvate, (C19H18P)2[Cu(C6H2Cl2S2)2]·2C2H6OS, (II), and methyltriphenylphosphonium bis(3,6‐dichlorobenzene‐1,2‐dithiolato‐κ2S,S′)cuprate(1−), (C19H18P)[Cu(C6H2Cl2S2)2], (III), have been synthesized and characterized by single‐crystal X‐ray diffraction. The X‐ray structure analyses of all three complexes confirm that the four donor S atoms form a slightly distorted square‐planar coordination arrangement around the central metal atom. An interesting finding for both the CuII and CuIII complexes, i.e. (II) and (III), respectively, is that the coordination polyhedra are principally the same and differ only slightly with respect to the interatomic distances. 相似文献
33.
《化学:亚洲杂志》2017,12(18):2426-2433
Exploring non‐precious‐metal‐based oxygen reduction reaction (ORR) electrocatalysts featuring high efficiency, low cost, and environmental friendliness is of great importance for the broad applications of fuel cells and metal–air batteries. In this work, ultrathin NiCo2O4 nanosheets deposited on 1D SnO2 nanotubes (SNT) were successfully fabricated through a productive electrospinning technique followed by a sintering and low‐temperature coprecipitation strategy. This hierarchically engineered architecture has ultrathin NiCo2O4 nanosheets uniformly and fully erected on both walls of tubular SNTs, which results in improved electrochemical activity as an ORR catalyst, in terms of positive onset potential and high current density, as well as superior tolerance to crossover effects and long‐term durability with respect to the commercial Pt/C catalyst. The excellent performance of SNT@NiCo2O4 composites may originate from their rationally designed hierarchical tubular nanostructure with completely exposed active sites and interconnected 1D networks for efficient electron and electrolyte transfer; this makes these composite nanotubes promising candidates to replace platinum‐based catalysts for practical fuel cell and metal–air battery applications. 相似文献
34.
《化学:亚洲杂志》2017,12(12):1381-1390
In this study, we synthesized [2]rotaxanes possessing three recognition sites—a dialkylammonium, an alkylarylamine, and a tetra(ethylene glycol) stations—in their dumbbell‐like axle component and dibenzo[24]crown‐8 (DB24C8) as their macrocyclic component. These [2]rotaxanes behaved as four‐state molecular shuttles: i) under acidic conditions, the DB24C8 unit encircled both the dialkylammonium and alkylarylammonium stations; ii) under neutral conditions, the dialkylammonium unit was the predominant station for the DB24C8 component; iii) under basic conditions, when both ammonium centers were deprotonated, the alkylarylamine unit became a suitable station for the DB24C8 component; and iv) under basic conditions in the presence of an alkali‐metal cation, the tetra(ethylene glycol) unit recognized the DB24C8 component through cooperative binding of the alkali‐metal ion. In addition, we observed that the [2]rotaxanes exhibited selective recognition for metal cations. These shuttling motions of the macrocyclic component proceeded reversibly. 相似文献
35.
《化学:亚洲杂志》2017,12(10):1043-1047
High‐silica RHO zeolite was directly synthesized using an alkali metal‐crown ether (AMCE) complex as organic structure‐directing agent (OSDA). Derived from the UV‐vis spectra and zeolite patterns, the crown ether‐cesium cation interaction was found to have crucial effect on the enhancement of silica content within the zeolite framework. The synthesized RHO zeolites possess up to four times larger silica/alumina ratio (SAR) values than that in their conventional form, which gives them extraordinarily rigid frameworks even after hydrothermal aging under 800 °C. Compared to commercial zeolites, copper‐exchanged high‐silica RHO zeolites demonstrate considerably high reaction activity in NOX removal, making them promising candidates for diesel exhaust treatment. 相似文献
36.
《化学:亚洲杂志》2017,12(7):816-821
NH‐bridged and pyrazine‐fused metallodiazaporphyrin dimers have been prepared from nickel(II) and copper(II) complexes of 3‐amino‐5,15‐diazaporphyrin by Pd‐catalyzed C−N cross‐coupling and oxidative dimerization reactions, respectively. The synergistic effects of the nitrogen bridges and meso ‐nitrogen atoms play major roles in enhancing the light‐harvesting properties and delocalization of an electron spin over the entire π‐skeletons of the metallodiazaporphyrin dimers. 相似文献
37.
Karen A. Gonzalez Sarah Kazemeini Dustyn C. Weber Paula A. Cordero Elizabeth M. Garcia Cory A. Rusinek 《Electroanalysis》2023,35(9):e202300098
Trace metals are required in the body as they play a significant role in several biochemical processes. Moreover, certain heavy metals are beneficial at appropriate levels. Copper (Cu), for example, is essential for red blood cell formation, bone strength, and infant growth. Despite these fundamental roles, Cu can become toxic at high levels. Other heavy metals such as lead (Pb), cadmium (Cd), manganese (Mn), and mercury (Hg), have been identified to cause acute and chronic health complications. For these reasons, rapid, real-time quantification of such metals in biological media is of interest to improving human health outcomes. Electrochemical methods offer numerous advantages, such as portability, capability to be miniaturized, low cost, and ease-of-use. In this review, we examine recent developments in electrochemical sensing for the detection of heavy metals in biological media. To meet the requirements for inclusion in this review, the electrochemical sensor must have been evaluated in biological media (blood, serum, sweat, saliva, urine, brain tissue/cells). Several applications are explored to examine recent advancements in electrochemical sensing within these matrices. Addressing the challenges through materials, device, and system innovations, it is expected that electrochemical sensing of heavy metals in biological media will facilitate future diagnoses and treatments in healthcare. 相似文献
38.
Alexandra Belcovici Carmen Ioana Fort Laura Elena Mureşan Ioana Perhaiţa Gheorge Borodi Graziella Liana Turdean 《Electroanalysis》2023,35(5):e202200395
ZnO nanoparticles (ZnO-NP) were prepared by a facile precipitation technique using di-isopropyl amine as precipitating agent. The morpho-structure and porosity of the as-prepared nano-powder were investigated by FT-IR analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), and BET analysis. By drop-casting, a composite film was deposited to obtain ZnO-NP-Nafion/GCE modified electrode. The modified electrode was investigated by cyclic voltammetry, electrochemical impedance spectroscopy, and square wave anodic stripping voltammetry (SWASV) for the detection of Pb2+, Cd2+, Cu2+, and Fe3+, and it was successfully applied for the detection of Pb2+ and Cu2+ in real water samples. 相似文献
39.
Dr. Peng Dong Tingna Shao Jinlian Li Xiaohui Zhang Prof. Yu Zhao Prof. Xinhong Zhao Prof. Guixian Li 《欧洲无机化学杂志》2023,26(33):e202300483
Cyclohexane epoxide, which contains highly active epoxy groups, plays a crucial role as an intermediate in the preparation of fine chemicals. However, controlling the epoxidation pathway of cyclohexene is challenging due to issues such as the allylic oxidation of cyclohexene and the ring opening of cyclohexane epoxide during the cyclohexene epoxidation process to form cyclohexane oxide. This review focuses on the structure-activity relationships and synthesis processes of various heterogeneous transition metal-based catalysts used in cyclohexene epoxidation reactions, including molybdenum(Mo)-based, tungsten(W)-based, vanadium(V)-based, titanium(Ti)-based, cobalt(Co)-based, and other catalysts. Initially, the mechanism of cyclohexene epoxidation by transition metal-based catalysts is examined from the perspective of catalytic active centers. Subsequently, the current research of cyclohexene epoxidation catalysts is summarized based on the perspective of catalyst support. Additionally, the differences between alkyl hydroperoxide, hydrogen peroxide (H2O2), and oxygen (O2) as oxidants are analyzed. Finally, the main factors influencing catalytic performance are summarized, and reasonable suggestions for catalyst design are proposed. This work provides scientific support for the advancement of the olefin epoxidation industry. 相似文献
40.
Eva Marie Freiberger Dr. Julien Steffen Natalie J. Waleska-Wellnhofer Anton Harrer Felix Hemauer Valentin Schwaab Prof. Dr. Andreas Görling Prof. Dr. Hans-Peter Steinrück Prof. Dr. Christian Papp 《Chemphyschem》2023,24(22):e202300510
This study addresses a fundamental question in surface science: the adsorption of halogens on metal surfaces. Using synchrotron radiation-based high-resolution X-ray photoelectron spectroscopy (XPS), temperature-programmed XPS, low-energy electron diffraction (LEED) and density functional theory (DFT) calculations, we investigated the adsorption and thermal stability of bromine on Rh(111) in detail. The adsorption of elemental bromine on Rh(111) at 170 K was followed in situ by XPS in the Br 3d region, revealing two individual, coverage-dependent species, which we assign to fcc hollow- and bridge-bound atomic bromine. In addition, we find a significant shift in binding energy upon increasing coverage due to adsorbate-adsorbate interactions. Subsequent heating shows a high thermal stability of bromine on Rh(111) up to above 1000 K, indicating strong covalent bonding. To complement the XPS data, LEED was used to study the long-range order of bromine on Rh(111): we observe a (√3×√3)R30° structure for low coverages (≤0.33 ML) and a star-shaped compression structure for higher coverages (0.33–0.43 ML). Combining LEED and DFT calculations, we were able to visualize bromine adsorption on Rh(111) in real space for varying coverages. 相似文献