Pallesenbendsen7903

Metal-organic frameworks (MOFs) have exhibited great potential for lithium-ion batteries (LIBs). However, to date, it is difficult to fabricate MOF electrode materials with regular shape and rational pore distribution by an economic approach, and the currently achieved MOF electrode materials usually have a relatively low initial Coulombic efficiency and poor cycle stability, which is not satisfactory for practical application. In this study, by using the recycled AlCl3 solution after dealloying treatment of Al-Si alloy, an evenly distributed brick-like Al-MOF with sub-micron size and rational pore distribution was synthesized for the first time. Because of the larger size and more macropores, the as-prepared Al-MOF electrode exhibits superior initial Coulombic efficiency as high as 96.6% for LIB anodes. Moreover, on account of the irregular crystal defects at the edge of the designed macropores, which result from unstable connection between the inorganic nodes (AlO6 octahedral cluster) and the organic linkers (PTA) and result in the formation of spherical nano-sized particles with better structural stability, the electrode materials show excellent cycle stability with discharge attenuation rate of 0.051%. The electrochemical performance considerably outperforms that of reported Al-MOF anodes and some representative MOF anodes in other studies. The robust realization of high initial Coulombic efficiency and cycle stability defines a critical step to capturing the full potential of MOF electrode materials in practical LIBs.AgSbF6 has been established as an effective catalyst for the hydroboration of structurally and electronically diverse isocyanates under ligand- and solvent-free conditions which selectively yielded either N-boryl formamides or N-boryl methylamines under different conditions. Further, various N-heterocycles can be selectively hydroborated using this simple catalytic system; pyridine derivatives undergo preferential 1,4 hydroboration whereas the formation of tetrahydroquinoline (after hydrolysis) via complete heterocycle hydrogenation was observed for quinolines.Palladium metallates containing 4-oxo-4H-chromene-3-carbaldehyde derived ONS donor Schiff bases were synthesized and their efficacy was tested in the direct amination of diosgenin - a phyto steroid. Based on the pharmacological importance of diosgenin, the obtained derivatives were exposed to study their effect on breast cancer cells where they significantly reduced the growth of cancer cells and left non-malignant breast epithelial cells unaffected. Among the derivatives, D3, D4 and D6 showed a better anti-proliferative effect and further analysis revealed that the D3, D4 and D6 derivatives markedly promoted cell cycle arrest and apoptosis by attenuation of the AKT1 signalling pathway.Two-dimensional transition metal dichalcogenides (TMDs) have emerged as promising catalysts for the hydrogen evolution reaction (HER). However, they typically require the engineering of additional actives sites (e.g. vacancies and dopants) and/or the application of large external strains to launch the HER on their basal planes. Herein, we investigate the HER proceeding on the experimentally available single-layer PdX2 (X = S, Se), a novel group of pentagonal TMDs with high amounts of intrinsic X vacancies, through density functional theory computations. Our results indicate that single-layer PdX2 nanosheets with low concentrations of X vacancies exhibit favorable hydrogen adsorption free energy (ΔGH*) values, which is desirable for facilitating the HER. Their HER performance can be greatly enhanced using small external strains, during which ΔGH* can reach the optimal value of 0 eV. Moreover, a kinetic analysis based on the explicit water model and charge extrapolation scheme demonstrates that the HER occurs on the PdX2 nanosheets according to the Volmer-Tafel mechanism with low energy barriers. This work highlights the realization of high HER activity on TMDs featuring unique structural characteristics.Structure- and mechanism-based redesign of the Fe(II)/2-oxoglutarate-dependent oxygenase AndA was performed. The function of AndA was expanded to catalyze a spiro-ring formation reaction from an isomerization reaction. The redesigned AndA variants produced two unnatural novel spiro-ring containing compounds through two and three consecutive oxidation reactions.The quantum size and spin-orbit coupling (SOC) effects play an important role in the electronic structure of photocatalytic materials with heavy elements such as Bi, Pb, Ir, Te, Sb, Sn, etc. How these two effects affect the conduction band (CB) or the valence band (VB) edge of a photocatalyst is not well understood. In this work, we investigated the quantum size and SOC effects on the CB and VB edges of BiVO4 (BVO) with a thickness of several atomic layers. The BVO is a good water oxidation photocatalyst but doesn't have the hydrogen reduction ability. We find that when the thickness of a BVO layer is smaller than 0.64 nm, the CB edge upshifts significantly because of the quantum size effect. But after including the SOC effect, the CB edge remains almost unchanged. selleck inhibitor The CB edge of BVO upshifts above the equilibrium redox potentials for H2/H2O with a thickness of ∼0.64 to 1.28 nm. Within this thickness, only the quantum size effect dominates and the SOC effect is very weak. Both the quantum size and SOC effects are insignificant as the thickness of the BVO layers increases to be larger than 1.28 nm. The results presented here provide an essential step toward the understanding and rational design of photocatalysts from both the quantum size and SOC effects.Ion-molecule reactions play key roles in the field of ion related chemistry. As a prototypical multi-channel ion-molecule reaction, the reaction H2 + NH2- → NH3 + H- has been studied for decades. In this work, we develop a new globally accurate potential energy surface (PES) for the title system based on hundreds of thousands of sampled points over a wide dynamically relevant region that covers long-range interacting configuration space. The permutational invariant polynomial-neural network (PIP-NN) method is used for fitting and the resulting total root mean squared error (RMSE) is extremely small, 0.026 kcal mol-1. Extensive dynamical and kinetic calculations are carried out on this PIP-NN PES. Impressively, a unique phenomenon of significant reactivity suppression by exciting the rotational mode of H2 is reported, supported by both the quasi-classical trajectory (QCT) and quantum dynamics (QD) calculations. Further analysis uncovers that exciting the H2 rotational mode would prevent the formation of the reactant complex and thus suppress the reactivity. The calculated rate coefficients for H2/D2 + NH2- agree well with the experimental results, which show an inverse temperature dependence from 50 to 300 K, consistent with the capture nature of this barrierless reaction. The significant kinetic isotope effect observed by experiments is well reproduced by the QCT computations as well.A computational study of the light-induced excited spin-state trapping (LIESST) in a number of Fe(II) spin crossover complexes, coordinated by monodentate, bidentate and multidentate ligands is carried out, with the goal to uncover the trend in the low temperature relaxation rate. A nine order of magnitude change in low temperature relaxation rate is observed among the complexes. The trend is rationalized in terms of the change in metal-ligand covalency, numerically estimated by the crystal orbital Hamiltonian population, thus influencing the back donation or delocalization of the electrons from the low-lying Fe(II)-centered molecular orbital to the empty low-lying ligand-centered π* antibonding molecular orbitals.Rh-catalyzed highly chemo- and enantioselective hydrogenation of chromone-2-carboxylic acids was successfully established for the first time, providing a wide range of enantiopure chromanone-2-carboxylic acids with excellent results (up to 97% yield and 99% ee) and high efficiency (up to 10 000 TON). The carboxylic group in the substrate was demonstrated to play a vital role and an enantio-induction mode was elucidated by DFT calculation. This hydrogenation protocol provided straightforward access to various bioactive chromanoids.The absence of a bandgap in pristine graphene severely restricts its application, and there is high demand for other novel two-dimensional (2D) materials. PC6 has recently emerged as a promising 2D material with a direct band gap and ultrahigh carrier mobility. In light of the remarkable properties of an intrinsic PC6 monolayer, it would be intriguing to find out whether a doped PC6 monolayer displays properties superior to the pure system. In this study, we have performed density functional theory calculations to understand the doping effects of both P-site and C-site substitution in PC6 and, for the first time, we discovered doping-related impurity-level anomalies in this system. We successfully explained why no donor or acceptor defect states exist in the band structures of XP-PC6 (X = C, Ge, Sn, O, S, Se, or Te). In group-IV-substituted systems, these dopant states hybridize with host states near the Fermi level rather than act as acceptors, which is deemed to be a potential way to tune the mobility of PC6. In the case of group-VI substitution, the underlying mechanism relating to doping anomalies arises from excess electrons occupying antibonding states.Herein, five aggregation-induced emission (AIE) photosensitizers (PSs) with D-π-A structures are smoothly designed and synthesized through donor and acceptor engineering. The photophysical properties and theoretical calculation results show that the synergistic effect of methoxy substituted tetraphenylethene (MTPE), 3,4-ethylenedioxythiophene can enhance the intramolecular charge transfer effect (ICT), and promote the intersystem crossing (ISC) process of the whole molecule. In these AIE-PSs, the best-performing AIE-PS (MTPE-DT-Py) has bright NIR (740 nm) emission, the highest 1O2 generation efficiency (5.9-fold that of Rose Bengal) and efficient mitochondrial targeting ability. Subsequently, PDT anti-cancer and anti-bacterial experiments indicate that MTPE-DT-Py could obviously target mitochondria and kill breast cancer cells (MCF-7), and selectively inactivate S. aureus (G(+)) under white light irradiation. This work mainly proposes a practical design strategy for high effect AIE-PSs and provides more excellent candidates for fluorescence imaging-guided photodynamic therapy.Early diagnosis of tumor markers is of great importance for the successful treatment of cancer. As a high-throughput and high-sensitivity detection technology, liquid suspension biochips based on quantum dot (QD) encoded microspheres have been widely used in the immunodetection of tumor markers. In this work, maleic anhydride grafted PLA (PLA-MA) microspheres based on quantum dot encoding were used as carriers for liquid phase suspension biochips for the immunoassay of tumor markers. PLA-MA fluorescent beads are prepared by embedding CdSe/ZnS quantum dots in PLA-MA using Shirasu porous glass (SPG) membrane emulsification technology, which has high fluorescence intensity, good stability, and good dispersion. Fluorescent immunoassays on dipsticks found that PLA-MA microspheres have high biological activity and good stability, which is conducive to immunoassays. Based on this, using the characteristics of CdSe/ZnS quantum dots and flow cytometry, monochromatic and two-color coding methods were developed, and 9 distinguishable coding beads were prepared.