Search

Two new ternary Cd(II) coordination polymers, [Cd2(L)(tbip)2]n (1) and {[Cd(L)0.5(1,4-NDC)]·0.4H2O}n (2) (H2tbip = 5-tert-butylisophthalic acid, 1,4-H2NDC = 1,4-naphthalenedicarboxylic acid and L = 1,4-bis(2-ethylbenzimidazol-1-ylmethyl)benzene), were hydrothermally synthesized and characterized via single-crystal X-ray diffraction, IR spectroscopy, powder X-ray diffraction (PXRD) and thermogravimetric analysis. 1 is a 1-D linear chain, while 2 exhibits a 3-D framework, which can be defined as a 3-D xah (sqc320) topology with the Schläfli symbol of {42.62.82}{46.64}. 1 and 2 remained stable in a pH range of 4.0–13.0 and 3.0–13.0, respectively. 1 and 2 displayed excellent luminescent sensing abilities for Fe3+ ions and tetracycline with high sensitivity and selectivity. [ABSTRACT FROM AUTHOR]

Exploring new noncovalent bonding motifs with reversibly tunable binding affinity is of fundamental importance in manipulating the properties and functions of supramolecular self‐assembly systems and materials. Herein, for the first time, we demonstrate a unique visible‐light‐switchable telluro‐triazole/triazolium‐based chalcogen bonding (ChB) system in which the Te moieties are connected by azobenzene cores. The binding strengths between these azo‐derived ChB receptors and the halide anions (Cl−, Br−) could be reversibly regulated upon irradiation by visible light of different wavelengths. The cis‐bidentate ChB receptors exhibit enhanced halide anion binding ability compared to the trans‐monodentate receptors. In particular, the telluro‐triazolium‐based ChB receptor can achieve both high and significantly photoswitchable binding affinities for halide anions, which enable it to serve as an efficient photocontrolled organocatalyst for ChB‐assisted halide abstraction in a Friedel–Crafts alkylation benchmark reaction. [ABSTRACT FROM AUTHOR]

Gold colloids with nanoparticles of different sizes were found to enhance the chemiluminescence (CL) of the luminol--[H.sub.2][O.sub.2] system, and the most intensive CL signals were obtained with 38-nm-diameter gold nanoparticles. UV--visible spectra, X-ray photoelectron spectra, and transmission electron microscopy studies were carded out before and after the CL reaction to investigate the CL enhancement mechanism. The CL enhancement by gold nanoparticles of the luminol--[H.sub.2][O.sub.2] system was supposed to originate from the catalysis of gold nanoparticles, which facilitated the radical generation and electron-transfer processes taking place on the surface of the gold nanoparticles. The effects of the reactant concentrations, the size of the gold nanoparticles, and some organic compounds were also investigated. Organic compounds containing OH, [NH.sub.2], and SH groups were observed to inhibit the CL signal of the luminol--[H.sub.2][O.sub.2]--gold colloids system, which made it applicable for the determination of such compounds.

Atomically precise copper clusters are highly desirable catalysts for electrocatalytic CO2 reduction reaction (CO2RR) and provide an ideal platform for elaborating structure–activity relationships. However, systematic comparative studies of Cu cluster isomers for electrocatalytic CO2RR are lacking because they are challenging to synthesize. A group of structurally precise Cu8 cluster isomers with different core structures (cube‐ and ditetrahedron‐shaped) were developed and investigated for highly active and selective CO2 reduction. Electrocatalytic measurements showed that the ditetrahedron‐shaped Cu8 cluster exhibited a higher FEHCOOH (≈92 %) at −1.0 V and higher selectivity than the cube‐shaped cluster. Theoretical investigations revealed different levels of competitiveness with the hydrogen evolution reaction on the respective core‐shaped Cu8 clusters and decreased free energies for the adsorbed HCOO* intermediates on the ditetrahedron‐shaped Cu8 clusters. [ABSTRACT FROM AUTHOR]

In this work, we calculate the mass spectrum of the bottom mesons with a modified nonrelativistic quark model by involving the screening effect, and explore their strong decay properties within the 3P0 model. Our results suggest that the B 1 (5 7 2 1) , B 2 ∗ (5 7 4 7) , B J (5 8 4 0) and B J (5 9 7 0) could be reasonably assigned as the B 1 ′ (1 P) , B (1 3 P 2) , B (2 1 S 0) and B (1 3 D 3) , respectively. The more precise measurements of the excited bottom mesons are crucial to confirm these assignments. [ABSTRACT FROM AUTHOR]