Heteroatom-doping has emerged as a transformative approach to producing high-performance catalysts, yet the current trial-and-error approach to optimize these materials remains ineffective. To enable the rational design of more efficient catalysts, models grounded in a deeper understanding of catalytic mechanisms are essential. Existing models, such as -band center theory, fall short in explaining the role of dopants, particularly when these dopants do not directly interact with reactants.
View Article and Find Full Text PDFBatteries based on sulfur cathodes offer a promising energy storage solution due to their potential for high performance, cost-effectiveness, and sustainability. However, commercial viability is challenged by issues such as polysulfide migration, volume changes, uneven phase nucleation, limited ion transport, and sluggish sulfur redox kinetics. Addressing these challenges requires insights into the structural, morphological, and chemical evolution of phases, the associated volume changes and internal stresses, and ion and polysulfide diffusion within the battery.
View Article and Find Full Text PDFIn this paper, we report an efficient red-green-blue (RGB) laser based on the stimulated Raman scattering (SRS) of ethanol. The wavelengths of the three-color laser are 631, 532, and 447 nm, respectively, and the gamut space that can cover is 116% of the Rec. 2020 standard gamut in the CIE1976 color space.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
February 2025
Stereospecific alternating copolymerization of different chiral cyclic esters is one feasible approach to enrich the structural diversity of copolyesters and tailor their properties. However, dramatically different reactivities of different cyclic esters let a perfectly stereospecific alternating polymerization of these cyclic esters be a challenge, thus the catalyst is required to balance their reactivities. Herein, a remarkable enantiomorphic site effect on chain end control was discovered and successfully utilized to balance the reactivities of highly reactive S, S-lactide (S, S-LA) and low reactive R, R-ethylglycolide (R, R-EG)/R, R-propylglycolide (R, R-PG) during their heterospecific alternating copolymerization.
View Article and Find Full Text PDFPolymer electrodes are drawing widespread attention to the future generation of lithium-ion battery materials. However, weak electrochemical performance of organic anode materials still exists, such as low capacity, low rate performance, and low cyclability. Herein, we successfully constructed a donor-acceptor thiophene-based polymer (PBT-1) by introducing an organoboron unit.
View Article and Find Full Text PDFThe tunable structure and other properties of organic materials suggest that they can potentially solve the shortcomings of traditional anodes such as graphite. We successfully introduced an organoboron unit into the thiophene-based polymer PBT-2 to construct a donor-acceptor polymer anode. The charge delocalization and LUMO energy level resulting from the unique structure of this material enabled good redox activity and a very stable electrochemical performance in electrochemical tests, with a reversible capacity of 262 mA h g at 0.
View Article and Find Full Text PDFThe application of selenium-based non-covalent bond catalysis in living cationic polymerization has rarely been reported. In this work, the cationic polymerization of -methoxystyrene (MOS) was performed using a bidentate selenium bond catalyst - a new water-tolerant Lewis acid catalyst. A polymer with controllable molecular weight and narrow molecular weight distribution can be obtained at room temperature, with a maximum molecular weight of 23.
View Article and Find Full Text PDFTo synthesize high molecular weight poly(phenolic ester) via a living ring-opening polymerization (ROP) of cyclic phenolic ester monomers remains a critical challenge due to serious transesterification and back-biting reactions. Both phenolic ester bonds in monomer and polymer chains are highly active, and it is difficult so far to distinguish them. In this work, an unprecedented selectively bifunctional catalytic system of tetra-n-butylammonium chloride (TBACl) was discovered to mediate the syntheses of high molecular weight salicylic acid-based copolyesters via a living ROP of salicylate cyclic esters (for poly(salicylic methyl glycolide) (PSMG), M =361.
View Article and Find Full Text PDFSynthesizing block-sequence-controlled poly(α-hydroxy acids) of three or four α-hydroxy acids remains challenging in one step. In this study, a strategy was employed using three monomers of -carboxyanhydrides (OCAs) consisting of one α-hydroxy acid (A), asymmetric cyclic diester (B and C, two different α-hydroxy acids of B and C), and symmetric cyclic diester (one α-hydroxy acid of D) with remarkably different activities toward a stereoselective, regioselective, and chemoselective initiator of a zirconium complex. Then, via a self-switchable approach, these monomers can be copolymerized in a well-controlled block sequence of A(BC)D and A(BC)A without an external stimulus.
View Article and Find Full Text PDFThree linear isoelectronic conjugated polymers PCC, PBC, and PBN are synthesized by Suzuki-Miyaura polycondensation for photocatalytic hydrogen (H ) production from water. PBN presented an excellent photocatalytic hydrogen evolution rate (HER) of 223.5 µmol h (AQY = 23.
View Article and Find Full Text PDFLiving copolymerization of mixed monomers can enrich the diversity of copolymer materials with well-defined performance via controlling both monomers and stereosequences. However, periodic sequence-controlled living copolymerization of same-type monomers with more than two components in synthetic polymer science remains a challenge. In this work, a new method of monomer-promoting asymmetric kinetic resolution-alternating copolymerization can let a tricomponent mixture of l-lactide (-LA or l-LA) and two enantiomeric isomers of racemic tropic acid cyclic esters (tropicolactone) be polymerized into sequence-controlled -(AAB)- type biodegradable copolyesters (the subscript S presents the configuration and A and B present lactic acid units and tropic acid units, respectively), and diblock copolymers of -(AAB)--(AAB)- can further be obtained upon addition of -LA (dLA).
View Article and Find Full Text PDFOrganic materials are promising candidates for future rechargeable batteries, owing to their high natural abundance and rapidly redox reaction. Elaborating the charge/discharge process of organic electrode is critical to unveil the fundamental redox mechanism of lithium-ion batteries (LIBs), but monitoring of this process is still challenging. Here, we report a nondestructive electron paramagnetic resonance (EPR) technique to real-time detect the electron migration step within polyimide cathode.
View Article and Find Full Text PDFHigh concentrations of active carriers on the surface of a semiconductor through energy/electron transfer are the core process in the photocatalytic hydrogen production from water. However, it remains a challenge to significantly improve photocatalytic performance by modifying simple molecular modulation. Herein, a new strategy is proposed to enhance the photocatalytic hydrogen evolution performance using boron and nitrogen elements to construct B←N coordination bonds.
View Article and Find Full Text PDFThe controllable synthesis of cyclic polylactide remains a challenging topic so far. In this work, a new strategy of one-pot step-wise ring-opening polymerization (ROP) followed by a back-biting reaction of ring closure was reported, in which one magnesium atrane-like complex {,-bis[3,5-di-cumyl-2-benzyloxy]-[2-(2-aminoethoxy)ethoxy]magnesium} was utilized to initiate the ROP of lactide using 4-dimethylaminopyridine as a co-catalyst; then, macrocyclic polylactides were liberated out increasing temperature after complete depletion of the monomer in which a back-biting reaction was utilized as a ring-closure method. The living feature at the first ROP stage can be proved well by the controllable molecular weights ranging from 3.
View Article and Find Full Text PDFBackground: The development of cisplatin resistance often results in cisplatin inefficacy in advanced or recurrent bladder cancer. However, effective treatment strategies for cisplatin resistance have not been well established.
Methods: Gene expression was measured by qRT-PCR and Western blotting.
Angew Chem Int Ed Engl
January 2022
Catalytic alkylation of stable alkenyl C-O electrophiles is synthetically appealing, but studies to date have typically focused on the reactions with alkyl Grignard reagents. We report herein a cross-electrophile reaction of alkenyl acetates with alkyl bromides. This work has enabled a new method for the synthesis of aliphatic alkenes from alkenyl acetates to be established that can be used to add more structural complexity and molecular diversity with enhanced functionality tolerance.
View Article and Find Full Text PDFLong non-coding RNAs (lncRNAs) have been reported to exert critical functions in the malignant development of many cancers. lncRNA HLA complex group 18 (HCG18) has been confirmed to have a promoting effect on various cancers. However, whether HCG18 functions in PC is still unclear.
View Article and Find Full Text PDFPoor charge separation is the main factor that limits the photocatalytic hydrogen generation efficiency of organic conjugated polymers. In this work, a series of linear donor-acceptor (D-A) type oligomers are synthesized by a palladium-catalyzed Sonogashira-Hagihara coupling of electron-deficient diborane unit and different dihalide substitution sulfur functionalized monomers. Such diborane-based A unit exerts great impact on the resulting oligomers, including distinct semiconductor characters with isolated lowest unoccupied molecular orbital (LUMO) orbits locating in diborane-containing fragment, and elevated LUMO level higher than water reduction potential.
View Article and Find Full Text PDFSynthesizing different types of sequence-controlled copolyesters can enrich the diversity of copolyesters and modify their properties more precisely, but it is still a challenge to synthesize a complicated sequence-controlled copolyester using different hydroxy acids in a living polymerization manner. In this work, a highly regioselective and stereoselective catalytic system was developed to synthesize biorenewable and biodegradable copolyesters of mandelic acid and lactic acid with isotactic-alternating, heterotactic-alternating, and ABAA-type precise and complicated sequences. Because of the regular incorporation of mandelic acid into polylactide, these sequence-controlled copolymers of mandelic acid and lactic acid show higher glass-transition temperatures than polylactide and a random copolymer.
View Article and Find Full Text PDFMonomer sequence controllable syntheses of copolymers, including copolyesters, remain a challenge in polymer science. Although alternating sequence-controlled copolymerization of -carboxyanhydrides (OCAs) can be achieved via using syndioselective initiators, the alternating copolymerization of lactic acid-derived -carboxyanhydride (LacOCA) with other monomers still suffers from a lack of highly syndioselective initiators. In this work, a highly syndioselective system for the ring-opening polymerization (ROP) of LacOCA was achieved using a bulky amine tris(phenolate) hafnium alkoxide initiator with a high value of 0.
View Article and Find Full Text PDFThe stereoselective ring-opening polymerization (ROP) of O-carboxyanhydrides (OCAs) remains a major challenge due to the easy epimerization of monomers. In this work, using a zinc alkoxide initiator, highly efficient ROP of enantiopure 5-methyl-1,3-dioxolane-2,4-dione (LacOCA), 5-benzyl-1,3-dioxolane-2,4-dione (PheOCA), and 5-(4-(benzyloxy)benzyl)-1,3-dioxolane-2,4-dione (Try(Bn)OCA) was achieved without obvious epimerization. Moreover, highly isoselective ROP of rac-LacOCA, rac-PheOCA, and rac-Try(Bn)OCA was successful with the highest isoselectivity of Pm = 0.
View Article and Find Full Text PDFTwo sodium/potassium tetradentate aminobisphenolate ion-paired complexes were synthesized and structurally characterized. These ion-paired complexes are efficient catalysts for the ring-opening polymerization of rac-lactide (rac-LA) in the presence of 5 equivalents BnOH as an initiator and the side reaction of epimerization can be suppressed well at low temperatures. The polymerizations are controllable, affording polylactides with desirable molecular weights and narrow molecular weight distributions; the highest molecular weight can reach 50.
View Article and Find Full Text PDFTubular hematite with high-concentration, uniform doping is regarded as a promising material for photoelectrochemical water oxidation. However, the high-temperature annealing commonly used for activating doped hematite inevitably causes deformation of the tubular structure and an increase in the trap states. In the present work, Sn-doped tubular hematite on fluorine-doped tin oxide (FTO) is successfully obtained at 750 °C from a Sn-coated FeOOH tube precursor.
View Article and Find Full Text PDFCrystalline aggregates containing metal cation clusters "wrapped" by reduced hydrocarbon anions have been presented. Initially, a dimeric complex (2) possessing a bimetallic KO core was synthesized from the reaction between an anthracene substituted boronic acid (2-(anthracen-9-yl)phenyl)(hydroxy)(mesityl)borane (1-H) and KN(SiMe) in THF solution. The B-O bond length (1.
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