A Hydrogen-Deficient Nickel–Cobalt Double Hydroxide for Photocatalytic Overall Water Splitting

Developing highly efficient and low-cost photocatalysts for overall water splitting has long been a pursuit for converting solar power into clean hydrogen energy. Herein, we demonstrate that a nonstoichiometric nickel–cobalt double hydroxide can achieve overall water splitting by itself upon solar light irradiation, avoiding the consumption of noble-metal co-catalysts. We employed an intensive laser to ablate a NiCo alloy target immersed in alkaline solution, and produced so-called L-NiCo nanosheets with a nonstoichiometric composition and O²⁻/Co³⁺ ions exposed on the surface. The nonstoichiometric composition broadens the band gap, while O²⁻ and Co³⁺ ions boost hydrogen and oxygen evolution, respectively. As such, the photocatalyst achieves a H₂ evolution rate of 1.7 μmol h⁻¹ under AM 1.5G sunlight irradiation and an apparent quantum yield (AQE) of 1.38 % at 380 nm.     

Benzidine/Quinoidal-Benzidine-Linked,Superbenzene-Based π-Conjugated Chiral Macrocycles and Cyclophanes

Synthesis of fully conjugated cyclophanes containing large-size polycyclic aromatics is challenging. Now, three benzidine-linked, hexa-peri-hexabenzocoronene (superbenzene)-based ortho-, para-, and meta-cyclophanes are synthesized through intermolecular Yamamoto coupling reaction of structurally pre-organized precursors. Subsequent oxidative dehydrogenation gave the corresponding quinoidal benzidine-linked cyclophanes. Their geometries were confirmed by X-ray crystallographic analysis and their electronic properties were investigated by electronic absorption, cyclic voltammetry, and DFT calculations. The quinoidal benzidine-linked cyclophanes show thermally populated paramagnetic activity with a relatively large singlet-triplet energy gap. Two enantiomers for the ortho-cyclophanes ( 1-NH and 1-N ) were isolated and their chiral figure-of-eight macrocyclic structures were identified. The cage-like cyclophanes 2-NH and 3-NH with concave surface can selectively encapsulate fullerene C₇₀.     

Asymmetric Coupling of Carbon-Centered Radicals Adjacent to Nitrogen: Copper-Catalyzed Cyanation and Etherification of Enamides

The first copper-catalyzed asymmetric cyanation and etherification reactions of enamides have been established, where a carbon-centered radical adjacent to a nitrogen atom (CRAN) is enantioselectively trapped by a chiral copper(II) species. Moreover, the asymmetric cyanation of vinyl esters was disclosed as well. These reactions feature very mild reaction conditions and high functional group tolerance, and give a series of chiral α-cyano amides, α-cyano esters and α-hemiaminals in good yields with excellent enantioselectivity. The chiral α-cyano amides can be easily converted into enantioenriched 1,2-diamines and amino acids.     

Rapid Capillary-Assisted Solution Printing of Perovskite Nanowire Arrays Enables Scalable Production of Photodetectors

Despite recent progress in producing perovskite nanowires (NWs) for optoelectronics, it remains challenging to solution-print an array of NWs with precisely controlled position and orientation. Herein, we report a robust capillary-assisted solution printing (CASP) strategy to rapidly access aligned and highly crystalline perovskite NW arrays. The key to the CASP approach lies in the integration of capillary-directed assembly through periodic nanochannels and solution printing through the programmably moving substrate to rapidly guide the deposition of perovskite NWs. The growth kinetics of perovskite NWs was closely examined by in situ optical microscopy. Intriguingly, the as-printed perovskite NWs array exhibit excellent optical and optoelectronic properties and can be conveniently implemented for the scalable fabrication of photodetectors.     

Chromophore-Assisted Proximity Labeling of DNA Reveals Chromosomal Organization in Living Cells

The spatial arrangement of chromosome within the nucleus is linked to genome function and gene expression regulation. Existing genome-wide mapping methods often rely on chemically crosslinking DNA with protein baits, which raises concerns of artifacts being introduced during cell fixation. By genetically targeting a photosensitizer protein to specific subnuclear locations, we achieved blue-light-activated labeling of local DNA with a bioorthogonal functional handle for affinity purification and sequence identification through next-generation sequencing. When applied to the nuclear lamina in human embryonic kidney 293T cells, it revealed lamina-associated domains (LADs) that cover 37.6 % of the genome. These LADs overlap with heterochromatin hallmarks and are depleted with CpG islands. This simple labeling method avoids the harsh treatment of chemical crosslinking and is generally applicable to the genome-wide high-resolution mapping of the spatial chromosome organization in living cells.     

A Layered Cationic Aluminum Oxyhydroxide as a Highly Efficient and Selective Trap for Heavy Metal Oxyanions

Cationic framework materials, especially pure inorganic cationic frameworks that can efficiently and selectively capture harmful heavy metal oxyanions from aqueous solution are highly desired yet scarcely reported. Herein, we report the discovery of a 2D cationic aluminum oxyhydroxide, JU-111, which sets a new benchmark for heavy metal oxyanion sorbents, especially for Cr^VI. Its structure was solved based on 3D electron diffraction tomography data. JU-111 shows fast sorption kinetics (ca. 20 min), high capture capacity (105.4 mg g⁻¹), and broad working pH range (3–10) toward Cr^VI oxyanions. Unlike layered double hydroxides (LDHs), which are poorly selective in the presence of CO₃²⁻, JU-111 retains excellent selectivity for Cr^VI even under a large excess of CO₃²⁻. These superior features coupled with the ultra-low cost and environmentally benign nature make JU-111 a promising candidate for toxic metal oxyanion remediation as well as other potential applications.     

The miracle role of lattice imperfections in benzene alkylation with methanol over mordenite

Mordenite (MOR) has demonstrated potential as a catalyst for alkylation due to high variability, intrinsic porosity, and outstanding stability. However, the contact probability of benzene and methanol has been limited by typical layered structures of MOR and there is no connection between layers. Here, we report the preparedness of H-MOR via a sequential post-treatment method based on a commercial MOR. H-MOR sample had appeared lattice imperfections inferred from characterization means. The samples were tested with benezene methylation reaction. Results show that the high conversion of benzene and the high selectivity of toluene were obtained from the miracle role of lattice imperfections in the H-MOR sample. Sequentially, based on the study of all catalyst structure and physical properties, a plausible reaction mechanism for the selectivity of the desired toluene was proposed.     

Benzofuran-isatin conjugates as potent VEGFR-2 and cancer cell growth inhibitors

A series of benzofuran-isatin conjugates 6a-l and 7a,b tethered by various alkyl linkers were synthesized and evaluated for their VEGFR-2 inhibitory activity and in vitro activity against a panel of cancer cell lines. Seven of them were comparable with or better than Sunitinib against all tested cancer cells, demonstrating benzofuran-isatin conjugates were potential anticancer candidates. The mechanism study revealed that VEGFR-2 was at least one of the targets for this kind of conjugates. The structure-activity relationship demonstrated that the carbon spacer between benzofuran and isatin moieties, substituents on the C-2 position of benzofuran moiety, and substituents on C-3 as well as C-5 position of isatin motif influenced the anticancer activity significantly, and the enriched structure-activity relationship may provide an insight for rational design of more effective conjugates.     

溶剂诱导翻转Pickering乳液用于原位循环使用酶催化剂

Separation and recycling of catalysts are crucial for realizing the objectives of sustainable and green chemistry but remain a great challenge, especially for enzyme biocatalysts. In this work, we report a new solvent-induced reversible inversion of Pickering emulsions stabilized by Janus mesosilica nanosheets (JMSNs), which is then utilized as a strategy for the in situ separation and recycling of enzymes. The interfacial active solid particle JMSNs is carefully characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), nitrogen sorption experiments, Fourier transform infrared (FT-IR) spectroscopy, and thermogravimetric analysis (TGA).The JMSNs are demonstrated to show order-oriented mesochannels with a large specific surface area, and the hydrophobic octylgroup is selectively modified on one side of the nanosheets. Furthermore, the inversion is found to be a fast process that is strongly dependent on the interfacial activity of the solid emulsifier JMSNs. Such a phase inversion is also a general process that can be realized in various oil/water phasic systems, including ethyl acetate-water, octane-water, and cyclohexane-water systems. By carefully analyzing the capacity of JMSNs with different surface wettabilities for phase inversion, a triphase contact angle (θ) close to 90° and a critical oil-water ratio of 1 : 2 are identified as the key factors to achieve solvent-induced phase inversion via a catastrophic phase inversion mechanism. Importantly, this reversible phase inversion is suitable for the separation and recycling of enzyme biocatalysts that are sensitive to changes in the reaction medium. Specifically, during the reaction, the organic substrates are dissolved in the oil droplets and the water-soluble catalysts are dispersed in the water phase, while a majority of the product is released into the upper oil phase and the enzyme catalyst is confined inside the water droplets in the bottom layer after phase inversion. The perpendicular mesochannels of JMSNs provide a highly accessible reaction interface, and their excellent interfacial activity allows for more than 10 rounds of consecutive phase inversions by simply adjusting the ratio of oil to water in the system. Using the enzymatic hydrolysis kinetic resolution of racemic acetate as an example, our Pickering emulsion system shows not only a 3-fold enhanced activity but also excellent recyclability. Because no sensitive chemical reagents are used in this phase inversion process, the intrinsic activities of the catalysts can be preserved even after seven cycles. The current study provides an alternative strategy for the separation and recycling of enzymes, in addition to revealing a new innovative application for Janus-type nanoparticles.     

Constructing spin-adiabatic states for the modeling of spin-crossing reactions. I. A shared-orbital implementation

In the modeling of spin-crossing reactions, it has become popular to directly explore the spin-adiabatic surfaces. Specifically, through constructing spin-adiabatic states from a two-state Hamiltonian (with spin-orbit coupling matrix elements) at each geometry, one can readily employ advanced geometry optimization algorithms to acquire a “transition state” structure, where the spin crossing occurs. In this work, we report the implementation of a fully-variational spin-adiabatic approach based on Kohn-Sham density functional theory spin states (sharing the same set of molecular orbitals) and the Breit-Pauli one-electron spin-orbit operator. For three model spin-crossing reactions (predissociation of N₂O, singlet-triplet conversion in CH₂, and CO addition to Fe(CO)₄), the spin-crossing points were obtained. Our results also indicated the Breit-Pauli one-electron spin-orbit coupling can vary significantly along the reaction pathway on the spin-adiabatic energy surface. On the other hand, due to the restriction that low-spin and high-spin states share the same set of molecular orbitals, the acquired spin-adiabatic energy surface shows a cusp (ie, a first-order discontinuity) at the crossing point, which prevents the use of standard geometry optimization algorithms to pinpoint the crossing point. An extension with this restriction removed is being developed to achieve the smoothness of spin-adiabatic surfaces.