Allisonchase9146

Materials with two-dimensional, geometrically frustrated, spin-1/2 lattices provide a fertile playground for the study of intriguing magnetic phenomena such as quantum spin liquid (QSL) behavior, but their preparation has been a challenge. In particular, the long-sought, exotic spin-1/2 star structure has not been experimentally realized to date. Here we report the synthesis of [(CH3)2(NH2)]3[CuII3(μ3-OH)(μ3-SO4)(μ3-SO4)3]·0.24H2O with an S = 1/2 star lattice. On the basis of the magnetic susceptibility and heat capacity measurements, the layered Cu-based compound exhibits antiferromagnetic interactions but no magnetic ordering or spin freezing down to 2 K. The spin-frustrated material appears to be a promising QSL candidate.Amidoallyl cations are appealing three-carbon synthons for the preparation of complex amine-containing carbocycles; however, methods to generate and utilize these reactive species are limited and underexplored compared to those for oxallyl cations. Here we disclose a bioinspired strain-driven ring opening of bicyclic methyleneaziridines to 2-amidopentadienyl cation intermediates that readily engage in Nazarov cyclizations. Advantages of this strategy include ease of generation and improved reactivity compared to 3-pentadienyl cations, control over the ultimate position of the alkene, the potential for high dr between vicinal stereocenters, and the ability to further elaborate the products to fully substituted aminocyclopentanes. Experimental and computational studies support a dual role for the Rh2Ln complex as both a nitrene transfer catalyst and a Lewis acid promoter, insight that provides a framework for the future development of asymmetric 2-imino-Nazarov cyclizations.This paper presents a new approach to classification of high-dimensional spectroscopy data and demonstrates that it outperforms other current state-of-the art approaches. The specific task we consider is identifying whether samples contain chlorinated solvents or not, based on their Raman spectra. We also examine robustness to classification of outlier samples that are not represented in the training set (negative outliers). A novel application of a locally connected neural network (NN) for the binary classification of spectroscopy data is proposed and demonstrated to yield improved accuracy over traditionally popular algorithms. Additionally, we present the ability to further increase the accuracy of the locally connected NN algorithm through the use of synthetic training spectra, and we investigate the use of autoencoder based one-class classifiers and outlier detectors. Finally, a two-step classification process is presented as an alternative to the binary and one-class classification paradigms. This process combines the locally connected NN classifier, the use of synthetic training data, and an autoencoder based outlier detector to produce a model which is shown to both produce high classification accuracy and be robust in the presence of negative outliers.To monitor d-glucose (Glu) in complex aqueous media with a high specificity, a conceptually new "selective capture and controllable detection" nanoreactor was explored. We designed and synthesized poly maleic anhydride-styrene-N-isopropylacrylamide-(4-aminophenyl) boronic acid [P(MAn-St-NIPAm-PBA)] to fabricate the nanoreactor. On the surface of the self-assembled, micelle-based nanoreactor, the stereo precise placement PBA provided a recognition unit in the block copolymer structure to boost the selective capture of Glu over other saccharides. P(MAn-St-NIPAm) served as the thermal sensitive moiety of the nanoreactor, which embedded with glucose oxidase and myoglobin-based catalyst in order to realize the controllable enzymolysis of Glu through temperature alteration. Once the nanoreactor was mixed with Glu, an obvious change in the UV-visible intensity of quinine produced in the multienzymolysis was observed. Glu in the rat microdialysates of brain ischemia was successfully monitored by the nanoreactor method, demonstrating the feasibility of constructing high-specificity nanoreactors for cerebral system applications.Arsenene, as an exotic representative of two-dimensional (2D) materials, has received great interest, yet the interest is mainly based on theoretical study. The reason for this is a restricted ability to operate the material from its synthesis to implementation. Nedisertib concentration Beginning with the production, electrochemical exfoliation has been found as an extremely effective method for the preparation of 2D materials from bulk materials. Here, for the first time, we demonstrate the electrochemical exfoliation of bulk black arsenic in the anhydrous electrolyte medium. Spectro- and microscopic analyses evidence micrometer lateral size few-layer arsenene in a netlike porous shape formed of 2D flakes. We demonstrate that the surfactant-free exfoliation successfully resulted in a stable dispersion for which only washing with the corresponding solvent was sufficient. This electrochemistry route for the black arsenic exfoliation toward few-layer arsenene will broaden the materials' scope applications in new-generation devices.Pulsed field gradient (PFG) NMR measurements, combined with a novel optimization method, are used to determine the composition of hydrocarbon mixtures of linear alkanes (C7-C16) in both the bulk liquid state and when imbibed within a porous medium of mean pore diameter 28.6 nm. The method predicts the average carbon number of a given mixture to an accuracy of ±1 carbon number and the mole fraction of a mixture component to within an average root-mean-square error of ±0.036 with just three calibration mixtures. Given that the method can be applied at any conditions of temperature and pressure at which the PFG NMR measurements are made, the method has the potential for application in characterising hydrocarbon liquid mixtures inside porous media and at the operating conditions relevant to, for example, hydrocarbon recovery and heterogeneous catalysis.2D-Ti3C2Tx MXene flake restacking and the small interlayer spacing of these MXenes limit their application in capacitive deionization. Here, we designed an all-MXene-based (L-S-Ti3C2Tx) flexible film electrode, enabled by large-size Ti3C2Tx (lateral dimensions of ⩾1 μm) MXene (L-Ti3C2Tx) nanosheets, which provided conductive pathways and were active substances, and by small-size Ti3C2Tx (500 nm) MXene (S-Ti3C2Tx) nanosheets, which were used as intercalation materials and active substances, for high-performance desalination in capacitive deionization applications. The as-synthesized L-S-Ti3C2Tx electrode achieved an excellent capacitance (169 F/g at 5 mV/s) and long-term cycling stability (maintained 91.7% of the initial capacitance after 5000 cycles). Additionally, these electrodes exhibited a high electroadsorption capacity (72 mg NaCl/g L-S-Ti3C2Tx, 10 mM NaCl solution). The improved electrochemical and desalination performance and outstanding long-term cycling stability can be attributed to the small Ti3C2Tx sheets that were introduced, which could be beneficial in exposing more active sites, facilitating electron transport, and shortening the diffusion path of Na ions.