Light-Driven Crawling of Molecular Crystals by Phase-Dependent Transient Elastic Lattice Deformation

The light-driven crawling of a molecular crystal that can form three phases, (α, β, and γ) is presented. Laser irradiation of the molecular crystal can generate phase-dependent transient elastic lattice deformation. The resulting elastic lattice deformation that follows scanning irradiation of a laser can actuate the different phases of molecular crystal to move with different velocity and direction. Because the γ phase has a large Young's modulus (ca. 26 GPa), a force of 0.1 μN can be generated under one laser spot. The generated force is sufficient to actuate the γ-formed molecular crystals in a wide dimensional range to move longitudinally at a velocity of about 60 μm min⁻¹, which is two orders of magnitude faster than the α and β phases.     

Palladium-Catalyzed Asymmetric [8+2] Dipolar Cycloadditions of Vinyl Carbamates and Photogenerated Ketenes

Higher-order cycloadditions, particularly [8+2] cycloadditions, are a straightforward and efficient strategy for constructing significant medium-sized architectures. Typically, configuration-restrained conjugated systems are utilized as 8π-components for higher-order concerted cycloadditions. However, for this reason, 10-membered monocyclic skeletons have never been constructed via catalytic asymmetric [8+2] cycloaddition with high peri- and stereoselectivity. Here, we accomplished an enantioselective [8+2] dipolar cycloaddition via the merger of visible-light activation and asymmetric palladium catalysis. This protocol provides a new route to 10-membered monocyclic architectures bearing chiral quaternary stereocenters with high chemo-, peri-, and enantioselectivity. The success of this strategy relied on the facile in situ generation of Pd-containing 1,8-dipoles and their enantioselective trapping by ketene dipolarophiles, which were formed in situ via a photo-Wolff rearrangement.     

Integrating bimetallic AuPd nanocatalysts with a 2D aza-fused π-conjugated microporous polymer for light-driven benzyl alcohol oxidation

Efficient catalytic system with low energy consumption exhibits increasing importance due to the upcoming energy crisis.Given this situation,it should be an admirable strategy for reducing energy input by effectively utilizing incident solar energy as a heat source during catalytic reactions.Herein,aza-fused7 r-conjugated microporous polymer(aza-CMP)with broad light absorption and high photothermal conversion efficiency was synthesized and utilized as a support for bimetallic AuPd nanocatalysts in light-driven benzyl alcohol oxidation.The AuPd nanoparticles anchored on aza-CMP(aza-CM P/Au_xPdy)exhibited excellent catalytic performance for benzyl alcohol oxidation under 50 mW/cm^2 light irradiation.The improved catalytic performance by the aza-CMP/Au_xPdy is attributed to the unique photothermal effect induced by aza-CMP,which can promote the catalytic benzyl alcohol oxidation occurring at Au Pd.This work presents a novel approach to effectively utilize solar energy for conventional catalytic reactions through photothermal effect.     

TiC/C core/shell nanowires arrays as advanced anode of sodium ion batteries

High-perfo rmance anodes of sodium ion batteries(SIBs)largely depends on rational architecture design and binder-free smart hybridization.Herein,we report TiC/C core/shell nanowires arrays prepared by a one-step chemical vapor deposition(CVD)method and apply it as the anode of SIBs for the first time.The conductive TiC core is intimately decorated with carbon shell.The as-obtained TiC/C nanowires are homogeneously grown on the substrate and show core/shell heterostructure and porous architecture with high electronic conductivity and reinforced stability.Owing to these merits,the TiC/C electrode displays good rate performance and outstanding cycling performance with a capacity of 135.3 mAh/g at 0.1 A/g and superior capacity retention of 90.14%after 1000 cycles at 2 A/g.The reported strategy would provide a promising way to construct binder-free arrays electrodes for sodium ion storage.     

Fabrication of Heterostructured Fe2TiO5–TiO2 Nanocages with Enhanced Photoelectrochemical Performance for Solar Energy Conversion

Photocatalysts with well‐designed compositions and structures are desirable for achieving highly efficient solar‐to‐chemical energy conversion. Heterostructured semiconductor photocatalysts with advanced hollow structures possess beneficial features for promoting the activity towards photocatalytic reactions. Here we develop a facile synthetic strategy for the fabrication of Fe₂TiO₅–TiO₂ nanocages (NCs) as anode materials in photoelectrochemical (PEC) water splitting cells. A hydrothermal reaction is performed to transform MIL‐125(Ti) nanodisks (NDs) to Ti–Fe–O NCs, which are further converted to Fe₂TiO₅–TiO₂ NCs through a post annealing process. Owing to the compositional and structural advantages, the heterostructured Fe₂TiO₅–TiO₂ NCs show enhanced performance for PEC water oxidation compared with TiO₂ NDs, Fe₂TiO₅ nanoparticles (NPs) and Fe₂TiO₅–TiO₂ NPs.     

Astaxanthin and its Effects in Inflammatory Responses and Inflammation-Associated Diseases: Recent Advances and Future Directions

Astaxanthin is a natural lipid-soluble and red-orange carotenoid. Due to its strong antioxidant property, anti-inflammatory, anti-apoptotic, and immune modulation, astaxanthin has gained growing interest as a multi-target pharmacological agent against various diseases. In the current review, the anti-inflammation mechanisms of astaxanthin involved in targeting for inflammatory biomarkers and multiple signaling pathways, including PI3K/AKT, Nrf2, NF-κB, ERK1/2, JNK, p38 MAPK, and JAK-2/STAT-3, have been described. Furthermore, the applications of anti-inflammatory effects of astaxanthin in neurological diseases, diabetes, gastrointestinal diseases, hepatic and renal diseases, eye and skin disorders, are highlighted. In addition to the protective effects of astaxanthin in various chronic and acute diseases, we also summarize recent advances for the inconsistent roles of astaxanthin in infectious diseases, and give our view that the exact function of astaxanthin in response to different pathogen infection and the potential protective effects of astaxanthin in viral infectious diseases should be important research directions in the future.     

A Molecular Thermochromic Ferroelectric

Molecular ferroelectrics have attracted considerable interests because of their easy and environmentally friendly processing, low acoustical impedance and mechanical flexibility. Herein, a molecular thermochromic ferroelectric, N,N′‐dimethyl‐1,4‐diazoniabicyclo[2.2.2]octonium tetrachlorocuprate(II) ([DMe‐DABCO]CuCl₄) is reported, which shows both excellent ferroelectricity and intriguing thermochromism. [DMe‐DABCO]CuCl₄ undergoes a ferroelectric phase transition from Pca2₁ to Pbcm at a significantly high Curie temperature of 413 K, accompanied by a color change from yellow to red that is due to the remarkable deformation of [CuCl₄]^2? tetrahedron, where the ferroelectric and paraelectric phases correspond to yellow and red, respectively. Combined with multiple bistable physical properties, [DMe‐DABCO]CuCl₄ would be a promising candidate for next‐generation smart devices, and should inspire further exploration of multifunctional molecular ferroelectrics.     

Reversibly Switching the Charge State and Adsorption Location of A Single Potassium Atom on Ultrathin CuO Films

Potassium (K) cations are spontaneously formed upon thermal deposition of low‐coverage K onto an ultrathin CuO monolayer grown on Cu(110) and they were explored by low‐temperature scanning tunneling microscopy (STM) and X‐ray photoemission spectroscopy. The formed K cations are highly immobile and thermally stable. The local work function around an individual K cation decreases by 1.5±0.3 eV, and a charging zone underneath it is established within about 1.0 nm. The cationic and neutral states of the K atom are switchable upon application of an STM bias voltage pulse, which is simultaneously accompanied by an adsorption site relocation.     

Irreversible Amide‐Linked Covalent Organic Framework for Selective and Ultrafast Gold Recovery

Design of stable adsorbents for selective gold recovery with large capacity and fast adsorption kinetics is of great challenge, but significant for the economy and the environment. Herein, we show the design and preparation of an irreversible amide‐linked covalent organic framework (COF) JNU‐1 via a building block exchange strategy for efficient recovery of gold. JNU‐1 was synthesized through the exchange of 4,4′‐biphenyldicarboxaldehyde (BA) in mother COF TzBA consisting of 4,4′,4′′‐(1,3,5‐triazine‐2,4,6‐triyl)trianiline (Tz) and BA with terephthaloyl chloride. The irreversible amide linked JNU‐1 gave good stability, unprecedented fast kinetics, excellent selectivity and outstanding adsorption capacity for gold recovery. X‐ray photoelectron spectroscopy along with thermodynamic study and quantum mechanics calculation reveals that the excellent performance of JNU‐1 for gold recovery results from the formation of hydrogen bonds C(N)?H???Cl and coordinate interaction of O and Au. The rational design of irreversible bonds as both inherent linkage and functional groups in COFs is a promising way to prepare stable COFs for diverse applications.     

New cytotoxic constituents in the water-soluble fraction from Momordicae Semen

Abstract

Two new lignans mubezhisol (1) and mubezhisal (2), together with twenty six known compounds (3–28) were isolated from water-soluble fraction from the semens of Momordica cochinchinensis. In the subsequent action evaluation, four saponins (4, 6, 13, 27), six lignans (1, 2, 16, 17, 22, 23), and one naphthoquinone (24) exhibited the significant cytotoxicity. The results indicated that various saponins and lignans were mainly responsible for the antitumor activities of Momordicae Semen.