Temperature-Responsive Formation Cycling Enabling LiF-Rich Cathode-Electrolyte Interphase.

Formation of LiF-rich cathode-electrolyte interphase is highly desirable for wide-temperature battery, but its application is hindered by the unwanted side reactions associated with conventional method of introducing fluorinated additives. Here, we developed an additive-free strategy to produce LiF-rich cathode electrolyte interphase (CEI) by low-temperature formation cycling. Using LiNi0.33Mn0.33Co0.33O2 as a model cathode, the atomic ratio of LiF in the CEI formed at -5 °C is about 17.7%, enhanced by ~550% compared to CEI formed at 25 °C (2.7%). The underlying mechanism is uncovered by both experiments and theoretic simulation, indicating that the decomposition of LiPF6 to LiF is transformed into spontaneous and exothermic on positively charged cathode surface and lowering the temperature shift chemical equilibrium towards the formation of LiF-rich CEI. Superior to conventional fluorinated additives, this approach is free from unwanted side reactions, imparting batteries with both high-temperature (60 oC) cyclability and low-temperature rate performance (capacity enhanced by 100% at 3 C at -20 oC). This low-temperature formation cycling to construct LiF-rich CEI is extended to various cathode systems, such as LiNi0.8Mn0.1Co0.1O2, LiCoO2, LiMn2O4, demonstrating the versatility and potential impact of our strategy in advancing the performance and stability of wide-temperature batteries and beyond.

Surface Defect and Wettability Engineering of Porous SnOx for Reliable Bioassays with High Selectivity and Wide Linear Dynamic Range.

Bioassay systems that can selectively detect biomarkers at both high and low levels are of great importance for clinical diagnosis. In this work, we report an enzyme electrode with an oxygen reduction reaction (ORR)-tolerant H2O2 reduction property and an air-liquid-solid triphase interface microenvironment by regulating the surface defects and wettability of nanoporous tin oxide (SnOx). The enzyme electrode allows the oxygen that is required for the oxidase catalytic reaction to be transported from the air phase to the reaction zone, which greatly enhances the enzymatic kinetics and increases the linear detection upper limit. Meanwhile, the ORR-tolerant H2O2 reduction property of SnOx catalysts achieved via oxygen vacancy engineering greatly reduces the interferent signals caused by oxygen and various easily oxidizable endogenous/exogenous species, which enables the selective detection of biomarkers at trace levels. The synergistic effect between these two novel qualities features a bioassay system with a wide dynamic linear range and high selectivity for the accurate detection of a wide range of biomarkers, such as glucose, lactic acid, uric acid, and galactose, offering the potential for reliable clinical diagnosis applications.

Organo-Photocatalytic Anti-Markovnikov Hydroamidation of Alkenes with Sulfonyl Azides: A Combined Experimental and Computational Study.

The construction of C(sp3)-N bonds via direct N-centered radical addition with olefins under benign conditions is a desirable but challenging strategy. Herein, we describe an organo-photocatalytic approach to achieve anti-Markovnikov alkene hydroamidation with sulfonyl azides in a highly efficient manner under transition-metal-free and mild conditions. A broad range of substrates, including both activated and unactivated alkenes, are suitable for this protocol, providing a convenient and practical method to construct sulfonylamide derivatives. A synergistic experimental and computational mechanistic study suggests that the additive, Hantzsch ester (HE), might undergo a triplet-triplet energy transfer manner to achieve photosensitization by the organo-photocatalyst under visible light irradiation. Next, the resulted triplet excited state 3HE* could lead to a homolytic cleavage of C4-H bond, which triggers a straightforward H-atom transfer (HAT) style in converting sulfonyl azide to the corresponding key amidyl radical. Subsequently, the addition of the amidyl radical to alkene followed by HAT from p-toluenethiol could proceed to afford the desired anti-Markovnikov hydroamidation product. It is worth noting that mechanistic pathway bifurcation could be possible for this reaction. A feasible radical chain propagation mechanistic pathway is also proposed to rationalize the high efficiency of this reaction.

Computational Insights into the Photoinduced Dimeric Gold-Catalyzed Divergent Dechloroalkylation of gem-Dichloroalkanes with Alkenes.

The employment of dinuclear Au(I) catalysts in photomediated modern organic transformations has attracted significant attention over the past decade, which commonly demonstrates unique catalytic performance compared with the corresponding mononuclear gold complexes. Nevertheless, detailed mechanisms of dinuclear gold catalysis remain ambiguous, and further mechanistic understanding is highly desirable. Herein, computational studies were carried out to gain mechanistic insights into the photoinduced dinuclear gold-catalyzed divergent dechloroalkylation of gem-dichloroalkanes. Computational results suggest that a proton transfer from the additive, Hantzsch ester (HE), to the base, guanidine, could lead to an ionic pair complex, which is ready to undergo excitation under blue light irradiation to result in the corresponding triplet excited state. Then, the excited complex might undergo oxidative quenching with the dinuclear gold photocatalyst [AuI-AuI]2+, via a single-electron-transfer (SET) step to afford an unusual [Au1/2-Au1/2]+ dinuclear species. The corresponding mononuclear gold catalyst, [AuI]+, however, is not ready to enable the analogous step to give a [Au0] species, which might account for the unique characteristics of dinuclear gold catalysis. Subsequently, the formed [Au1/2-Au1/2]+ intermediate could trigger a Cl-atom transfer from dichloromethane in an inner-sphere manner to furnish a critical chloromethyl radical. Next, the resulting chloromethyl radical could attack the alkenyl moiety of substrates to generate the corresponding alkyl radicals. Then, three possible mechanistic pathways were explored to rationalize the substrate-dependent divergent transformations in this protocol. The main factors responsible for the diversified transformations were discussed.

A novel parallel ant colony optimization algorithm for mobile robot path planning.

With the continuous development of mobile robot technology, its application fields are becoming increasingly widespread, and path planning is one of the most important topics in the field of mobile robot research. This paper focused on the study of the path planning problem for mobile robots in a complex environment based on the ant colony optimization (ACO) algorithm. In order to solve the problems of local optimum, susceptibility to deadlocks, and low search efficiency in the traditional ACO algorithm, a novel parallel ACO (PACO) algorithm was proposed. The algorithm constructed a rank-based pheromone updating method to balance exploration space and convergence speed and introduced a hybrid strategy of continuing to work and killing directly to address the problem of deadlocks. Furthermore, in order to efficiently realize the path planning in complex environments, the algorithm first found a better location for decomposing the original problem into two subproblems and then solved them using a parallel programming method-single program multiple data (SPMD)-in MATLAB. In different grid map environments, simulation experiments were carried out. The experimental results showed that on grid maps with scales of 20 $ \times $ 20, 30 $ \times $ 30, and 40 $ \times $ 40 compared to nonparallel ACO algorithms, the proposed PACO algorithm had less loss of solution accuracy but reduced the average total time by 50.71, 46.83 and 46.03%, respectively, demonstrating good solution performance.

Computational insights into the zeolite-supported gold nanocluster-catalyzed ethanol dehydrogenation to acetaldehyde.

Zeolite-supported gold nanoclusters play increasingly important roles in heterogeneous catalysis and exhibit unique catalytic properties for ethanol dehydrogenation to acetaldehyde. Nevertheless, the reaction mechanism and potential roles of the zeolite-encapsulated gold nanoclusters during the catalytic process remain unclear. Herein, computational studies were carried out to gain mechanistic insights into ethanol dehydrogenation to acetaldehyde under both aerobic and anaerobic conditions catalyzed by a silicalite-1 zeolite-encapsulated Au3 cluster cation (Au3+-S1). The presence of O2 can significantly promote the ethanol dehydrogenation catalyzed by Au3+-S1. A feasible mechanistic pathway could be initiated via the O2 induced H-atom transfer (HAT) step from the hydrogen of the hydroxyl group to afford ethoxy and OOH radical species. Subsequently, the OOH induced second HAT from α-C-H of the ethoxy intermediate could follow to afford the acetaldehyde product. Moreover, the possible confinement and stabilization effect of the zeolite channels on the ethanol dehydrogenation reaction was discussed.

A Novel Algorithm for Solving the Prize Collecting Traveling Salesman Problem Based on DNA Computing.

DNA computing is a new pattern of computing that combines biotechnology and information technology. As a new technology born in less than three decades, it has developed at an extremely rapid rate, which can be attributed to its advantages, including high parallelism, powerful data storage capacity, and low power consumption. Nowadays, DNA computing has become one of the most popular research fields worldwide and has been effective in solving certain combinatorial optimization problems. In this study, we use the Adleman-Lipton model based on DNA computing for solving the Prize Collecting Traveling Salesman Problem (PCTSP) and demonstrate the feasibility of this model. Then, we design a simulation experiment of the model to solve some open instances of PCTSP. The results illustrate that the model can satisfactorily solve these instances. Finally, the comparison with the results of the Clustering Search algorithm and the Greedy Stochastic Adaptive Search Procedure/Variable Neighborhood Search method reveals that the optimal solutions obtained by this simulation experiment are significantly superior to those of the other two algorithms in all instances. This research also provides a method for proficiently solving additional combinatorial optimization problems.

Copper-Catalyzed Radical Allene C(sp2 )-H Cyanation.

While the hydrogen atom abstraction (HAA) from C(sp3 )-H bond has been well explored, the radical-mediated chemo- and regio-selective functionalization of allenic C(sp2 )-H bond via direct HAA from C(sp2 )-H bond of allene remains an unsolved challenge in synthetic chemistry. This is primarily due to inherent challenges with addition of radical intermediates to allenes, regioselectivity of HAA process, instability of allenyl radical toward propargyl radical et al. Herein, we report a copper catalyzed allenic C(sp2 )-H cyanation of an array of tri- and di-substituted allenes with exceptional site-selectivity, while mono-substituted allene was successfully cyanated, albeit with a low yield. In the developed strategy, steric N-fluoro-N-alkylsulfonamide, serving as precursor of hydrogen atom abstractor, plays a crucial role in achieving the desired regioselectivity and avoiding addition of N-centered radical to allene.

A Bioorthogonal Decaging Chemistry of N-Oxide and Silylborane for Prodrug Activation both In Vitro and In Vivo.

Bioorthogonal decaging chemistry with both fast kinetics and high efficiency is highly demanded for in vivo applications but remains very sporadic. Herein, we describe a new bioorthogonal decaging chemistry between N-oxide and silylborane. A simple replacement of "C" in boronic acid with "Si" was able to substantially accelerate the N-oxide decaging kinetics by 106 fold (k2: up to 103 M-1 s-1). Moreover, a new N-oxide-masked self-immolative spacer was developed for the traceless release of various payloads upon clicking with silylborane with fast kinetics and high efficiency (>90%). Impressively, one such N-oxide-based self-assembled bioorthogonal nano-prodrug in combination with silylborane led to significantly enhanced tumor suppression effects as compared to the parent drug in a 4T1 mouse breast tumor model. In aggregate, this new bioorthogonal click-and-release chemistry is featured with fast kinetics and high efficiency and is perceived to find widespread applications in chemical biology and drug delivery.

Reacting Molecular Oxygen with Butanone under Visible Light Irradiation: A General Aerobic Oxidation of Alkenes, Sulfides, Phosphines, and Silanes.

Here, we present a novel oxidation technique by reacting molecular oxygen with butanone under visible light irradiation. This method enables the mild oxidation of various functionalized compounds, including olefins, sulfides, phosphines, and silanes. Preliminary mechanistic experiments and theoretical calculations suggest that visible light triggers molecular oxygen to produce singlet oxygen in butanone. This singlet oxygen then reacts with butanone, producing an active oxidizing species.

Construction of α-Acyloxy Ketones via Photoredox-Catalyzed O-H Insertion of Sulfoxonium Ylides with Carboxylic Acids.

Herein, a photoredox-catalyzed insertion of sulfoxonium ylides with carboxylic acids was advanced under mild and simple conditions, offering a practical approach for preparing α-acyloxy ketones with a broad scope of carboxylic acids. A combined experimental and computational study suggests that this reaction proceeds via a stepwise proton-assisted electron transfer mechanism.

Solving the Min-Max Clustered Traveling Salesmen Problem Based on Genetic Algorithm.

The min-max clustered traveling salesmen problem (MMCTSP) is a generalized variant of the classical traveling salesman problem (TSP). In this problem, the vertices of the graph are partitioned into a given number of clusters and we are asked to find a collection of tours to visit all the vertices with the constraint that the vertices of each cluster are visited consecutively. The objective of the problem is to minimize the weight of the maximum weight tour. For this problem, a two-stage solution method based on a genetic algorithm is designed according to the problem characteristics. The first stage is to determine the visiting order of the vertices within each cluster, by abstracting a TSP from the corresponding cluster and applying a genetic algorithm to solve it. The second stage is to determine the assignment of clusters to salesmen and the visiting order of the assigned clusters. In this stage, by representing each cluster as a node and using the result of the first stage and the ideas of greed and random, we define the distances between each two nodes and construct a multiple traveling salesmen problem (MTSP), and then apply a grouping-based genetic algorithm to solve it. Computational experiments indicate that the proposed algorithm can obtain better solution results for various scale instances and shows good solution performance.

Cobalt-Promoted Noble-Metal Catalysts for Efficient Hydrogen Generation from Ammonia Borane Hydrolysis.

Ammonia borane (AB) has been regarded as a promising material for chemical hydrogen storage. However, the development of efficient, cost-effective, and stable catalysts for H2 generation from AB hydrolysis remains a bottleneck for realizing its practical application. Herein, a step-by-step reduction strategy has been developed to synthesize a series of bimetallic species with small sizes and high dispersions onto various metal oxide supports. Superior to other non-noble metal species, the introduction of Co species can remarkably and universally promote the catalytic activity of various noble metals (e.g., Pt, Rh, Ru, and Pd) in AB hydrolysis reactions. The optimized Pt0.1%Co3%/TiO2 catalyst exhibits a superhigh H2 generation rate from AB hydrolysis, showing a turnover frequency (TOF) value of 2250 molH2 molPt-1 min-1 at 298 K. Such a TOF value is about 10 and 15 times higher than that of the monometal Pt/TiO2 and commercial Pt/C catalysts, respectively. The density functional theory (DFT) calculation reveals that the synergy between Pt and CoO species can remarkably promote the chemisorption and dissociation of water molecules, accelerating the H2 evolution from AB hydrolysis. Significantly, the representative Pt0.25%Co3%/TiO2 catalyst exhibits excellent stability, achieving a record-high turnover number of up to 215,236 at room temperature. The excellent catalytic performance, superior stability, and low cost of the designed catalysts create new prospects for their practical application in chemical hydrogen storage.

Mechanistic Insights into Enantioselective C(sp3 )-H Acylation to Construct α-Amino Ketones via Photoredox and Ni(II) Dual Catalysis: A DFT Study.

The development of the merger of a Ni(II) catalyst with an appropriate photocatalyst under visible-light irradiation provides a new strategy for realizing direct functionalization of C(sp3 )-H bonds. Mechanistically, whether the reduction of Ni catalyst to form a Ni(0) species is necessary in the dual catalysis still remains under debate. Herein, DFT calculations were carried out to gain a mechanistic insight into the enantioselective acylation of α-amino C(sp3 )-H bonds to furnish α-amino ketones via photoredox and Ni dual catalysis. A feasible mechanistic pathway for the Ni catalysis via the Ni(I)-Ni(III)-Ni(II)-Ni(III)-Ni(I) cycle is suggested with the sequential elementary steps of oxidative addition, single electron reduction, radical addition, and reductive elimination in leading to the final product, whereas a nickel catalytic cycle, Ni(I)-Ni(0)-Ni(II)-Ni(III)-Ni(I), might not be feasible for the photoredox and Ni dual-catalyzed acylation of α-amino C(sp3 )-H bonds. The origin of the stereoselectivity for this reaction is also discussed, which could be attributed to the minimization of the steric hindrance between the alkyl moiety of radical part and phenyl group of the chiral ligand.

Computational Understanding of Dual Gold and Photoredox-Catalyzed Regioselective Thiosulfonylation of Alkenes.

Herein, a computational work was carried out to gain mechanistic insights into dual gold and photoredox-catalyzed regioselective thiosulfonylation of alkenes with PhSO2SCF3. Computational results suggest that it is more favorable for the complex of Au(I) with PhSO2SCF3 (INT1), instead of an Au(I) catalyst or individual substrates, to quench the excited *[Ru]II photocatalyst in a single-electron oxidative manner to afford [Ru]III. The complexation of the Au(I) catalyst with PhSO2SCF3 could lead to a substantially lowered energy level of the lowest unoccupied molecular orbital, which may be mainly responsible for the feasibility of INT1 in quenching the excited photocatalyst. The resultant single-electron reduced complex, subsequently, is ready to undergo a S-S bond cleavage to form an Au(I)-SCF3 species and a benzenesulfonyl radical. Next, the yielded Au(I)-SCF3 species could undergo single-electron oxidation by [Ru]III to afford an Au(II) intermediate. Subsequently, the binding with an alkyl radical for the formed Au(II) species could occur to further convert to an Au(III) species, from which the final product can be furnished by a reductive elimination step and the Au(I) catalyst is regenerated. Thus, an Au(I)/Au(II)/Au(III)/Au(I) catalytic cycle is suggested to mainly account for the regioselective thiosulfonylation of alkenes.

Iron-catalyzed dual decarboxylative coupling of α-amino acids and dioxazolones under visible-light to access amide derivatives.

An iron-catalyzed decarboxylative C-N coupling of α-amino acids with dioxazolones is described herein to synthesize amide derivatives under visible-light. The desired products can be given in good to excellent yields under simple, mild, and oxidant-free conditions. This protocol provides a practical route for the transformation of α-amino acids to the corresponding amides. Computational studies were carried out to shed light on the mechanism of this reaction.

Aerosol Spray Drying Guided Synthesis of Ultrasmall Alloyed Bimetallic Nanoparticles Supported on Silica for Catalytic Semihydrogenation.

Supported bimetallic nanoparticles (NPs) with ultrasmall sizes and homogeneous alloying are attractive for catalysis. However, facile synthesis of this type of material remains very challenging. Here, the aerosol drying impregnation method for rapid, scalable, and general synthesis of silica-supported bimetallic NPs is proposed. The method relies on aerosol spray drying to promote the mixing and dispersing of binary metal precursors on SiO2 . It is capable of controlling the composition and size of bimetallic NPs and avoids the use of expensive metal complex salts and complicated experiment procedures. Twelve permutations combining a noble metal (Pd, Ru, and Pt) and a base one (Fe, Co, Ni, and Cu) with ultrasmall sizes (1.4-2.2 nm in average size), uniform dispersion, and good alloying are synthesized. Interesting activity and selectivity trends in catalytic semihydrogenation of phenylacetylene over the supported Pd-based NPs can be observed. The silica-supported PdNi NPs deliver both high activity and styrene selectivity. Spectroscopic and density functional theory calculation results reveal the improved chemoselectivity originated from the suitably down-shifted d-band center of the PdNi NPs inducing an increased energy barrier for overhydrogenation and a weakened styrene adsorption.

Facile preparation of dihydro-1,4-benzothiazine derivatives via oxidative ring-expansion of 2-aminobenzothiazoles with olefins.

A concise and efficient approach to prepare dihydro-1,4-benzothiazine derivatives is described via oxidative ring-expansion of 2-aminobenzothiazoles with olefins under metal-free conditions. This protocol is applicable for a wide range of readily accessible 2-aminobenzothiazoles and olefins with moderate-to-good yields. The [4+2] heteroannulation between the intermediacy of oxidative ring-opening of 2-aminobenzothiazoles and olefins is suggested to rationalize the formation of the product.

Solving the Family Traveling Salesperson Problem in the Adleman-Lipton Model Based on DNA Computing.

The Family Traveling Salesperson Problem (FTSP) is a variant of the Traveling Salesperson Problem (TSP), in which all vertices are divided into several different families, and the goal of the problem is to find a loop that concatenates a specified number of vertices with minimal loop overhead. As a Non-deterministic Polynomial Complete (NP-complete) problem, it is difficult to deal with it by the traditional computing. On the contrary, as a computer with strong parallel ability, the DNA computer has incomparable advantages over digital computers when dealing with NP problems. Based on this, a DNA algorithm is proposed to deal with FTSP based on the Adleman-Lipton model. In the algorithm, the solution of the problem can be obtained by executing several basic biological manipulations on DNA molecules with O ( N2 ) computing complexity ( N is the number of vertices in the problem without the origin). Through the simulation experiments on some benchmark instances, the results show that the parallel DNA algorithm has better performance than traditional computing. The effectiveness of the algorithm is verified by deducing the algorithm process in detail. Furthermore, the algorithm further proves that DNA computing, as one of the parallel computing methods, has the potential to solve more complex big data problems.

[2 + 2 + 1] Cycloaddition of N-tosylhydrazones, tert-butyl nitrite and alkenes: a general and practical access to isoxazolines.

N-Tosylhydrazones have proven to be versatile synthons over the past several decades. However, to our knowledge, the construction of isoxazolines based on N-tosylhydrazones has not been examined. Herein, we report the first demonstrations of [2 + 2 + 1] cycloaddition reactions that allow the facile synthesis of isoxazolines, employing N-tosylhydrazones, tert-butyl nitrite (TBN) and alkenes as reactants. This process represents a new type of cycloaddition reaction with a distinct mechanism that does not involve the participation of nitrile oxides. This approach is both general and practical and exhibits a wide substrate scope, nearly universal functional group compatibility, tolerance of moisture and air, the potential for functionalization of complex bioactive molecules and is readily scaled up. Both control experiments and theoretical calculations indicate that this transformation proceeds via the in situ generation of a nitronate from the coupling of N-tosylhydrazone and TBN, followed by cycloaddition with an alkene and subsequent elimination of a tert-butyloxy group to give the desired isoxazoline.