Search

To investigate microstructural evolution and plastic deformation under tension, the rapid solidification processes of the Ni47Co53 alloy are first simulated by molecular dynamics methods at cooling rates of 1011, 1012 and 1013 K s−1. Then, the uniaxial tension simulation study was conducted on a single crystal, polycrystal and metallic glass, which were formed during the rapid solidification. The results show that the dislocation loops evolution in the crystal is caused by the slips and proliferation of stacking faults, and in terms of plastic deformation, the single crystal is carried by stacking faults, while a polycrystal is carried by grain boundaries. A metallic glass formed at the critical cooling rate and crystallized under tension, the plastic deformation is carried by grain boundaries and stacking faults in metallic glass. Ultimately, the stacking faults are the most resistant to plastic deformation. This study has great significance for the study of the mechanical properties of single crystals, polycrystals and metallic glass. [ABSTRACT FROM AUTHOR]

A square-planar nickel(ii) dithiolate complex is an active molecular catalyst for both photoreduction of protons from water with a turnover number (＞1500) and electroreduction of protons from weakly acidic solutions with remarkable turnover frequencies (5575 s−1 at −1.92 V and 1441 s−1 at −1.61 V vs. SCE). DFT calculations provide in-depth insight into the catalytic cycle of the electrochemical reaction, suggesting that the sulfur atoms play crucial roles in proton exchange and hydrogen formation. [ABSTRACT FROM AUTHOR]

A simple 4-aniline boron-dipyrromethene (BODIPY) dye (1) was developed as a highly sensitive acidic pH fluorescent probe excitable with visible light based on a photoinduced electron transfer (PeT) mechanism. The pH titration indicates that the fluorescence intensity increases more than 500-fold within the pH range of 4.12-1.42 with a pKa value of 3.24 in methanol-water (1 : 1, v/v) solution, which is valuable for studying strongly acidic conditions. Density functional theory (DFT) calculations reproduce the fluorescence off-on behavior. 1 has also been used as a fluorescent chemosensor for the visual detection of dissolved carbon dioxide (CO2) gas. The underlying mechanism of the sensing process is rationalized. This probe can be recovered by bubbling nitrogen (N2) gas into CO2-treated solutions for over 10 cycles. In addition, two logic gates (OR and INH) have been achieved at the molecular level by changing the initial states of system 1 and chemical inputs. [ABSTRACT FROM AUTHOR]

Various decomposition products of C–O ether bond cleavage have been trapped in supramolecular architectures as templates based on hydrothermal reaction of three-component metal–carboxylate–phen, which not only results in the formation of [5]pseudorotaxane structure, 3D porous framework and supramolecular structure, but also provides directly crystallographic evidence to explain how the C–O ether bond breaks during decomposition. [ABSTRACT FROM AUTHOR]

Three novel luminescent metal–organic frameworks [Zn(1,2-BBOMB)(4,4′-bipy)1/2]n(1), [Zn2(1,3-BBOMB)2(4,4′-bipy)]n(2) and [Zn4(1,2-BBOMB)4(bpp)2]n(3) have been synthesized by combining the conformationally flexible V-shaped long multicarboxylate ligands and the rigid 4,4′-bipy or flexible bpp ligands with zinc ions under hydrothermal conditions. It is worth mentioning that the layers observed in the three compounds can be reduced to the same 6-connected topological net with (22·48·65) symbol. These complexes display a structural evolution from a two-dimensional (2D) polyrotaxane and polycatenane framework to a three-dimensional (3D) architecture with coexistence of polyrotaxane, polycatenane and interdigitation. The three species contain loops and rods that are interlaced in a highly rare parallel fashion, but with twofold (2D → 2D), triply (2D → 2D) and triply (2D → 3D) entangled features in complexes 1, 2and 3, respectively. Furthermore, the rotaxane-like interactions between the loops and the rods exhibit a progressive change from one loop interacting with a single rod, to one loop interacting with two identical rods, to finally one loop interacting with two conformationally different rods in complexes 1, 2and 3, respectively. Photoluminescence studies revealed that these complexes are potential violet, blue and green luminescent materials. The thermal stabilities of these complexes were also discussed. [ABSTRACT FROM AUTHOR]

Luminescent acentric and homochiral coordination compounds, which possess new topological networks, multiple helical structures and NLO properties, have been generated through the control of a versatile asymmetric ligand as well as inorganic anions, and this suggests a new protocol for preparing acentric and chiral materials. [ABSTRACT FROM AUTHOR]

A simple 4-aniline boron-dipyrromethene (BODIPY) dye (1) was developed as a highly sensitive acidic pH fluorescent probe excitable with visible light based on a photoinduced electron transfer (PeT) mechanism. The pH titration indicates that the fluorescence intensity increases more than 500-fold within the pH range of 4.12-1.42 with a pKa value of 3.24 in methanol-water (1 : 1, v/v) solution, which is valuable for studying strongly acidic conditions. Density functional theory (DFT) calculations reproduce the fluorescence off-on behavior. 1 has also been used as a fluorescent chemosensor for the visual detection of dissolved carbon dioxide (CO2) gas. The underlying mechanism of the sensing process is rationalized. This probe can be recovered by bubbling nitrogen (N2) gas into CO2-treated solutions for over 10 cycles. In addition, two logic gates (OR and INH) have been achieved at the molecular level by changing the initial states of system 1 and chemical inputs.