查看更多>>摘要：The saline and buffered environment in actual wastewater imposes higher demands on Fenton and Fenton-like catalytic systems.This study developed a MoS2 co-catalytic Fe2O3 Fenton-like system with controllable Lewis acid-base sites,achieving efficient treatment of various model pollutants and actual industrial wastewater under neutral buffered environment.The acidic microenvironment struc-tured by the edge S sites(Lewis basic sites)in the MoS2/Fe2O3 catalyst is susceptible to the influence of Lewis acidic sites constructed by Mo and Fe element,affecting catalytic performance.Optimizing the ratio of precursor amounts ensures the stable presence of the acidic microenvironment on the surface of catalyst,enabling the beneficial co-catalytic effect of Mo sites to be realized.Furthermore,it transcends the rigid constraints imposed by the Fenton reaction on reaction environments,thereby expanding the applicability of commonplace oxides such as Fe2O3 in actual industrial water remediation.
查看更多>>摘要：Single-nucleotide variants(SNVs)are crucial in disease development,but their accurate detection is challenging due to their low abundance and interference from wild-type targets.Although nucleic acid analogs like peptide nucleic acids(PNAs)have been used for SNV detection,they often lack programmable sensitivity and specificity due to poorly calculated thermodynamics and kinetics.Here,we present a computational method for calculating the stacking energy of PNA and DNA hybrids,leveraging nearest neighbor param-eters.Validation against experimental data from 16 sequences under varied hybridization conditions yielded good agreement using Bland-Altman analysis,with all data points falling within the confidence interval.Our findings indicate that PNA-DNA hybridization is thermodynamically more stable and exhibits kinetics 140-fold faster than DNA-DNA hybridization for identical sequences.Utilizing this computational framework,we designed PNA toehold probes,which were screened via simulations and experiments.This combined approach facilitated the identification of highly sensitive and specific PNA toehold probes for single point mutation detection via strand displacement reaction.Our results demonstrate the successful application of PNA toehold probes for detecting point mutations with high sensitivity and specificity,achieving a selective amplification of approximately 200-fold for variants with a variant allele fre-quency(VAF)of 0.5％using quantitative polymerase chain reaction.
查看更多>>摘要：Macrocyclic compounds are of great interest for their ability to capture guest molecules into their cavities.In particular,host-guest in-teraction plays a crucial role in the formation of supramolecular compounds.Herein,two host-guest supramolecular compounds,[Al8(OH)8(L)16]·2HL(HL@AIOC-166,HL=4-lodobenzoic acid)and[Al8(OH)8(L)8(L1)8]·2DMF(DMF@AIOC-166,HL1=isoamyl alcohol),are acquired by introducing different types of guest components based on the internal pore cavities of the aluminum molecular ring[Al8(OH)8(L)16](AIOC-166).The inclusion of these guests is attributed to the presence of abundant hydrophilic OH serving as the hy-drogen bond donors inward the ring cavity.Host-guest compounds usually exhibit superior nonlinear optical(NLO)response due to the existence of guest molecules that could change symmetry,dipole moments,charge distributions,etc.Unexpectedly,the AIOC-166 achieved the best NLO results,although it had no guest molecules inside its molecular ring,which breaks the traditional concept.The reason for this trend can be explained by the difference in intermolecular force rather than intramolecular interaction,mainly related to the amount and strength of π…π and C-I…π interactions in different compounds.This work investigates the effect of host-guest interaction on NLO,representing a new perspective for designing optical limiting materials.
查看更多>>摘要：Potassium ion batteries(PIBs)are of great interest owing to the low cost and abundance of potassium resources,while the sluggish diffusion kinetics of K+in the electrode materials severely impede their practical applications.Here,self-hybridized BiOCl0,sBr0.5 with a floral structure is assembled and used as anode for PIBs.Based on the systematic theoretical calculation and experimental analysis,the unbalance of charge distribution between Cl and Br atoms leads to an enhanced built-in electric field and a larger interlayer spac-ing,which can enhance the K+diffusion.Furthermore,the K+insertion causes the energetic evolution of polar states in the BiOClo.5Bro.5 crystal framework,where the dynamic correlation between the K+and the halogen atoms leads to the formation of hole-like polarons,which significantly improves the K+diffusion and reaction kinetics during the charging/discharging process,giving important implica-tions to design the electrode materials with high electrochemical performance by engineering the interaction between electronic structure and interface.Therefore,the BiOCl0.sBr0.5 anode obtains an excellent performance of 171 mAh·g-1 at 1 A·g-1 over 2000 cycles in PIBs.
查看更多>>摘要：Converting CO2 into valuable chemicals is an effective means to alleviate environmental pressure and the depletion of oil resources.Among them,polymers derived from the copolymerization of PO and CO2 have been widely studied because of their excellent proper-ties.To meet the expansion of the application range of CO2-based polymers,regulation of the CU in the polymer is imperative.Based on the understanding of the relationship between catalyst synergy and structure,we designed a new generation of polyester-based polymeric catalysts APEPC-R and RPEPC-N with discretely distributed active centers to achieve the synthesis of CO2-based polymers with regulated CU(from 50％to 90％).The discrete arrangement of catalyst active centers was demonstrated by 1H NMR and UV-vis characterization.Benefiting from multi-site synergy,high molecular weight(Mn＞100 kg/mol)CO2-based copolymers with CU among 50％-90％were successfully synthesized and their properties were firstly investigated.This work not only contributes to enriching the scope of the application of CO2-based copolymers but also provides a new platform for the development of a new generation of cata-lysts.
查看更多>>摘要：Previous studies have demonstrated linear polymers embedded with B←N units display efficient photocatalytic hydrogen evolution performance,but their limited structural tunability restricts photogenerated carrier dynamics modulation.Current researches mainly focus on linear polymers,while the study of B←N units in the field of two-dimension conjugated polymers(2DCPs)photocatalytic hy-drogen evolution remains an uncultivated ground.Herein,three 2DCPs containing B←N units were synthesized and their photocata-lytic hydrogen production performance was investigated.Among them,the BN-Tz exhibited the best property with a hydrogen pro-duction rate of 89.5 μmol·h-1,while BN-Ph and BN-TPB were only 26.4 and 8.5 μmolh-1,respectively.Comprehensive analyses showed that the remarkable photocatalytic ability of BN-Tz catalyst was mainly attributed to its superior transport and separation of photogenerated carriers,as well as the ability to construct a stronger built-in electric field and better planarity.Meanwhile,it was found that the manipulation of the electronic properties of the structures connected to the B←N unit could effectively regulate the molecular polarity,thus achieving the control of the electronic structure of the materials.This work extends the application of materi-als containing B←N units in photocatalysis and lays a good foundation for the subsequent design of photocatalysts containing B←N units.
查看更多>>摘要：Concise assembly of spirooxindoles is of great significance but a challenging task in modern organic synthesis.Described herein is an unusual base-promoted[4+2]spiroannulation of rarely used isatin-derived β-silylcarbinols with o-halogen aromatic ketones,which enables rapid and modular synthesis of six-membered carbocyclic spirooxindoles in high yields with excellent functional group toler-ance(＞50 examples).Mechanistic experiments revealed that this reaction involved a Peterson olefination,Michael addition and in-tramolecular C(sp3)arylation cascade.The variegated synthetic derivatization of target products and successful construction of bioac-tive molecules further illustrate the synthetic potential in spirooxindole-related drug discovery.
查看更多>>摘要：Covalent organic framework(COF)is a desirable platform to tailor electronic properties for improving photocatalytic performances.However,the study on excited-state configurations that determine photogenerated carrier dynamics has long been neglected.Herein,we concentrate on the molecular design of β-ketoenamine-linked COFs to drive their photoisomerization via the excited-state in-tra-molecular proton transfer(ESIPT),which can induce the partial keto-to-enol tautomerization and accordingly rearrange the pho-toinduced charge distribution.We demonstrate that the push-pull electronic effect of functional side groups attached on the frame-work linkers is directly correlated with the ESIPT process.The phenylene linkers modified with electron-withdrawing cyano-groups re-inforce the ESIPT-induced tautomerization,leading to the in situ partial enolization for extended n-conjugation and rearranged elec-tron-hole distribution.In contrast,the electron-rich linkers limit the photoisomerization of COF and suppress the photoinduced elec-tron accumulation.Thus,the maximum hydrogen evolution rate is achieved by the cyano-modified COF,reaching as high as 162.72 mmol·g-1·h-1 with an apparent quantum efficiency of 13.44％at 475 nm,which is almost 11.5-fold higher than those of analogous COFs with electron-rich linkers.Our work opens up an avenue to control over the excited-state structure transformation for enhanced photochemical applications.
查看更多>>摘要：We herein describe a Cp*RhⅢ-catalyzed C(sp3)-H mono-arylation of 8-methylquinolines with benign arylsilanes.The use of 1-adamantane carboxylic acid can benefit the efficiency in this transformation,and AgF was both activator and reoxidant.Control ex-periments indicated inability of C-H cleavage in determining the rate of the reaction.
查看更多>>摘要：We present a strategy that effectively modulate the d-band electronic structure of the active center by strain effect and interatomic orbital hybridization.This strategy efficiently promotes the kinetic process of the ethanol oxidation reaction(EOR)in alkaline media.In the intermetallic Pd3Pb nanowires,the introduction of Pb not only causes the lattice expansion of Pd but also achieves the interatomic orbital hybridization bonding with Pd.Such interatomic orbital hybridization effect and tensile strain effect can effectively achieve a co-regulation of the d-band electronic structure of Pd,which directly affects the adsorption behavior of intermediate on Pd for EOR.Hence,the intermetallic Pd3Pb nanowires demonstrate enhanced EOR activity and anti-poisoning ability against COads.Theoretical calculations show that the enhanced OH*adsorption ability and the low energy barrier for the oxidative dehydrogenation of ethanol are the keys to high EOR activity and stability of the intermetallic Pd3Pb nanowires.
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