Enhanced H₂ dissociation and H spillover facilitates the in situ generation of Fe0 at the Cu/Fe3O4 catalyst interfaces, which promotes C2–C3 production through a photothermal CO hydrogenation pathway powered by solar energy. More details are discussed in the article by Zhong et al. on pages 791—797.
Cooperativity, fluxionality, biocompatibility and self-adaption are four essential criteria in designing new generation artificial cell walls. The cover story adopted the image of Feitian in armor who was playing pipa and Chinese landscape to interpret these four characteristics of the artificial cell wall. General methods of fabricating artificial cell walls were introduced in this review and interpreted in the cover story. The artificial cell walls are able to play significant roles in the fields of cytoprotection, cellular metabolic regulation, etc., and are potential in the field of cell therapy and tissue engineering. More details are discussed in the article by Huang et al. on pages 715—728.
High pressure is an effective means to manipulate the crystal structure and optical properties of hybrid metal halides. By pressure treatment of the zero-dimensional metal halide BTPP2ZnBr4 (BTPP = Benzyl triphenyl phosphonium), a 7-fold enhanced blue emission is obtained. In-situ synchrotron powder X-ray diffraction and Raman experiments show that the phenomenon arises from an irreversible structural compression. More details are discussed in the article by Li et al. on pages 524—530.
Photothermal hydrogenation of carbon monoxide (CO) holds the potential to generate valuable C2+ chemicals using renewable solar energy. However, its activity and selectivity towards C2—C3 alkanes are limited compared to conventional thermal catalysis. In this study, we developed a robust catalyst consisting of Cu/Fe3O4 nanoparticles on Mo2CTx MXene, showing enhanced photothermal C2—C3 production. The Cu component plays a crucial role in H2 dissociation and subsequent H spillover, facilitating the in situ generation of Fe0 in Fe5C2 active sites and thus efficiently promoting photothermal CO hydrogenation. As a result, we achieved a 51.3% C2+ selectivity and 78.5% CO conversion at a high gas hourly space velocity (GHSV) of 12000 mL·gcat−1·h−1 and 2.5 MPa in a flow reactor at 320 °C. The overall C2—C3 yield reached 23.6% with Cu/Fe3O4/Mo2CTx catalysts, marking a 2.8-fold increase compared to the performance of the bare Fe3O4/Mo2CTx catalyst.
Dendronized polymers (DenPols) with tunable shape and surface property have been recognized as a type of promising unimolecular nanomaterials. However, it still has lacked a rapid and efficient approach to the facile synthesis of DenPols with high-generation and well-defined structures. Herein, we report a “m+n” grafting-onto strategy combined with the copper-catalyzed azide-alkyne cycloaddition (CuAAC) reaction with reaction-enhanced reactivity of intermediates (RERI) mechanism for synthesizing DenPols Gm+n by attaching n-generation dendrons (Gn) onto the m-generation DenPols Gm. In this “m+n” grafting-onto strategy, the DenPols Gm (m = 1, 2) bearing 1,3-triazido branches on the repeating unit were capable of RERI effect that guaranteed the CuAAC reaction in an extremely efficient way with ultrafast kinetics to synthesize third-, fourth- and fifth-generation DenPols (G1+2, G1+3, G1+4, G2+2, and G2+3) with near quantitative grafting density and narrow distribution. Moreover, these resultant DenPols Gm+n had more terminal groups per repeating unit due to the three branches of 1,3-triazido structure, exhibiting valuable potential opportunities for molecular surface engineering. The development of this “m+n” grafting-onto strategy with RERI mechanism not only presents a new avenue for ultrafast preparing DenPols but also holds great promise for preparing unimolecular materials with more functional terminal groups.
The ion-selective porous membrane is the key component in osmotic energy conversion, and optimizing its permeability and selectivity is crucial for improving output performance. Here, to construct a permeability and selectivity synergistically enhanced osmotic energy generator, the surface and space charge synergistically enhanced 3D composite membrane is prepared by inserting sulfonated hydrogels into the 3D ion channels with tunable surface charge. The membrane's selectivity is improved from 0.66 to 0.94 by increasing the charge density on the membrane surface and the spatial charge density of the membrane. The experimental and simulation results showed that the synergistic enhancement of the spatial and surface charges significantly improved the electrostatic interactions between the ions and the ion channels, which led to the enhancement of selectivity, net ionic fluxes, and output performance. The space charge improved composite membrane presents an advanced power density of about 6.4 W·m–2 under a 50-fold concentration gradient, which is nearly 2 times that of the phase inversion membrane without hydrogels. Our study provides a promising solution for constructing high-performance osmotic energy generators.
Regioselective C3-nitration of indazoles is still challenging owing to the electron-deficient of C3-position. A variety of C3-nitroindazoles have been successfully prepared though TBN-mediated N—N bond formation with air and sequential 1,3-migration of nitro group. Moreover, the nitration reaction could be easily performed in the gram scales and applied in modifications of drugs at late-stage. More details are discussed in the article by Mo et al. on pages 393—398.
Stereoselective construction of 2-deoxy-glycosidic linkages has been achieved by the 1,2-sulfur migration/glycosylation and desulfurization strategy; however, current protocols suffer from harsh reaction conditions and unsatisfactory stereoselectivity, particularly during the 1,2-S-migration/glycosylation step. With 2-O-resided (o-alkynyl)benzoate and anomeric p-methoxyphenylsulfenyl groups as the initiating and migrating groups, respectively, a novel protocol for the efficient synthesis of 2-deoxy-glycosides via the 1,2-sulfur migration/glycosylation-desulfurization strategy has been established, which is featured by the mild and catalytic reaction conditions, expanded substrate scope, as well as good to excellent diastereoselectivity. Mechanism studies determined hyperconjugation-stabilized oxocarbenium ion as the key intermediate, achieving high 1,2-trans stereocontrol through thermodynamic, steric, as well as electrostatic effects. This provides the fresh insight for the operative mechanism of the 1,2-sulfur migration/glycosylation and desulfurization strategy, further corroborated by the elaborately designed testing reactions and DFT calculations. Moreover, the synthetic potential of the newly established protocol was examined by the practical synthesis of natural product, culminating in the acquisition of digoxin from acetylated digoxigenin in 25% overall yield through an 8-step longest linear sequence.
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