Search

Although possessing well‐defined nanostructures and excellent multi‐electron redox properties, polyoxometalate clusters have poor intrinsic electrical conductivity and are prone to aggregation due to large surface energy, which makes them difficult to be fully utilized when applying as electrode materials for lithium‐ion batteries. In this paper, monodisperse K7MnV13O38 (MnV13) clusters are achieved by rationally utilizing nano‐sized high conductive carbon dots (CDs) as stabilizers. Benefiting from the fully exposed redox sites of MnV13 clusters (high utilization rate) and sufficient interfaces with carbon dots (extra interfacial energy storage), the optimized MnV13/10CDs anode delivers a high discharge capacity up to 1348 mAh g−1 at a current density of 0.1 A g−1 and exhibits superb rate/cycling capabilities. Density functional theory (DFT) calculations verify that ionic archway channels are formed between MnV13 and CDs, eliminating the bandgap and greatly improving the electron/ion conductivity of MnV13 and CDs. This paper paves a brand‐new way for synthesis of monodisperse clusters and maximization of extra interfacial energy storage. [ABSTRACT FROM AUTHOR]

The present paper reports a remote carbon‐to‐carbon boryl migration via an intramolecular 1,4‐B/Cu shift, which establishes an in situ stereospecific electrophilic trap on the alkene moiety. The synthetic application is developed to prepare functionalized cyclopentenes by means of a palladium‐catalyzed regioselective intramolecular coupling that completes a strategic cyclopropanation and generates valuable structural bicyclic systems. The mechanism is characterized by DFT (density functional theory) calculations which showed that the 1,4‐migration proceeds through an intramolecular, nucleophilic attack of the copper‐alkyl moiety on the boron atom bonded to the C(sp2), leading to a 5‐membered boracycle structure. The computation of the 1,3‐ and 1,4‐B/Cu shifts is also compared as is the impact of the endo‐ or exocyclic alkene on the reaction kinetics. [ABSTRACT FROM AUTHOR]

The capacity to manipulate magnetization in 2D dilute magnetic semiconductors (2D‐DMSs) using light, specifically in magnetically doped transition metal dichalcogenide (TMD) monolayers (M‐doped TX2, where M = V, Fe, and Cr; T = W, Mo; X = S, Se, and Te), may lead to innovative applications in spintronics, spin‐caloritronics, valleytronics, and quantum computation. This Perspective paper explores the mediation of magnetization by light under ambient conditions in 2D‐TMD DMSs and heterostructures. By combining magneto‐LC resonance (MLCR) experiments with density functional theory (DFT) calculations, we show that the magnetization can be enhanced using light in V‐doped TMD monolayers (e.g., V‐WS2, V‐WSe2). This phenomenon is attributed to excess holes in the conduction and valence bands, and carriers trapped in magnetic doping states, mediating the magnetization of the semiconducting layer. In 2D‐TMD heterostructures (VSe2/WS2, VSe2/MoS2), the significance of proximity, charge‐transfer, and confinement effects in amplifying light‐mediated magnetism is demonstrated. We attributed this to photon absorption at the TMD layer that generates electron–hole pairs mediating the magnetization of the heterostructure. These findings will encourage further research in the field of 2D magnetism and establish a novel design of 2D‐TMDs and heterostructures with optically tunable magnetic functionalities, paving the way for next‐generation magneto‐optic nanodevices. [ABSTRACT FROM AUTHOR]

The stability of hybrid organic–inorganic halide perovskite semiconductors remains a significant obstacle to their application in photovoltaics. To this end, the use of low‐dimensional (LD) perovskites, which incorporate hydrophobic organic moieties, provides an effective strategy to improve their stability, yet often at the expense of their performance. To address this limitation, supramolecular engineering of noncovalent interactions between organic and inorganic components has shown potential by relying on hydrogen bonding and conventional van der Waals interactions. Here, the capacity to access novel LD perovskite structures that uniquely assemble through unorthodox S‐mediated interactions is explored by incorporating benzothiadiazole‐based moieties. The formation of S‐mediated LD structures is demonstrated, including one‐dimensional (1D) and layered two‐dimensional (2D) perovskite phases assembled via chalcogen bonding and S–π interactions. This involved a combination of techniques, such as single crystal and thin film X‐ray diffraction, as well as solid‐state NMR spectroscopy, complemented by molecular dynamics simulations, density functional theory calculations, and optoelectronic characterization, revealing superior conductivities of S‐mediated LD perovskites. The resulting materials are applied in n‐i‐p and p‐i‐n perovskite solar cells, demonstrating enhancements in performance and operational stability that reveal a versatile supramolecular strategy in photovoltaics. [ABSTRACT FROM AUTHOR]

Vanadium nitride (VN) is a potential cathode material with high capacity and high energy density for aqueous zinc batteries (AZIBs). However, the slow kinetics resulting from the strong electrostatic interaction of the electrode materials with zinc ions is a major challenge for fast storage. Here, VN clusters with nitrogen‐vacancy embedded in carbon (C) (Nv‐VN/C‐SS‐2) are prepared for the first time to improve the slow reaction kinetics. The nitrogen vacancies can effectively accelerate the reaction kinetics, reduce the electrochemical polarization, and improve the performance. The density functional theory (DFT) calculations also prove that the rapid adsorption and desorption of zinc ions on Nv‐VN/C‐SS‐2 can release more electrons to the delocalized electron cloud of the material, thus adding more active sites. The Nv‐VN/C‐SS‐2 exhibits a specific capacity and outstanding cycle life. Meanwhile, the quasi‐solid‐state battery exhibits a high capacity of 186.5 mAh g−1, ultra‐high energy density of 278.9 Wh kg−1, and a high power density of 2375.1 W kg−1 at 2.5 A g−1, showing excellent electrochemical performance. This work provides a meaningful reference value for improving the comprehensive electrochemical performance of VN through interface engineering. [ABSTRACT FROM AUTHOR]

Non‐fullerene acceptors (NFAs) have recently emerged as pivotal materials for enhancing the efficiency of organic solar cells (OSCs). To further advance OSC efficiency, precise control over the energy levels of NFAs is imperative, necessitating the development of a robust computational method for accurate energy level predictions. Unfortunately, conventional computational techniques often yield relatively large errors, typically ranging from 0.2 to 0.5 electronvolts (eV), when predicting energy levels. In this study, the authors present a novel method that not only expedites energy level predictions but also significantly improves accuracy , reducing the error margin to 0.06 eV. The method comprises two essential components. The first component involves data cleansing, which systematically eliminates problematic experimental data and thereby minimizes input data errors. The second component introduces a molecular description method based on the electronic properties of the sub‐units comprising NFAs. The approach simplifies the intricacies of molecular computation and demonstrates markedly enhanced prediction performance compared to the conventional density functional theory (DFT) method. Our methodology will expedite research in the field of NFAs, serving as a catalyst for the development of similar computational approaches to address challenges in other areas of material science and molecular research. [ABSTRACT FROM AUTHOR]

A CoMoS composite is synthesized to combine the benefits of cobalt and molybdenum sulfides as an anodic material for advanced lithium‐ion batteries (LIBs). The synthesis is accomplished using a simple two‐step hydrothermal method and the resulting CoMoS nanocomposites are subsequently encapsulated in a carbonized polydopamine shell. The synthesis procedure exploited the self‐polymerization ability of dopamine to create nitrogen‐doped carbon‐coated cobalt molybdenum sulfide, denoted as CoMoS@NC. Notably, the de‐lithiation capacity of CoMoS and CoMoS@NC is 420 and 709 mAh g⁻1, respectively, even after 100 lithiation/de‐lithiation cycles at a current density of 200 mA g⁻1. Furthermore, excellent capacity retention ability is observed for CoMoS@NC as it withstood 600 consecutive lithiation/de‐lithiation cycles with 94% capacity retention. Moreover, a LIB full‐cell assembly incorporating the CoMoS@NC anode and an NMC‐532 cathode is subjected to comprehensive electrochemical and practical tests to evaluate the performance of the anode. In addition, the density functional theory showcases the increased lithium adsorption for CoMoS@NC, supporting the experimental findings. Hence, the use of dopamine as a nitrogen‐doped carbon shell enhanced the performance of the CoMoS nanocomposites in experimental and theoretical tests, positioning the material as a strong candidate for LIB anode. [ABSTRACT FROM AUTHOR]

Herein, a remarkable achievement in the synthesis and characterization of an atomically precise copper‐hydride nanocluster, [Cu41(SC6H3F2)15Cl3(P(PhF)3)6(H)25]2− via a mild one‐pot reaction is presented. Through X‐ray crystallography analysis, it is revealed that [Cu41(SC6H3F2)15Cl3(P(PhF)3)6(H)25]2− exhibits a unique shell–core–shell structure. The inner Cu29 kernel is composed of three twisted Cu13 units, connected through Cu4 face sharing. Surrounding the metal core, two Cu6 metal shells, resembling a protective sandwich structure are observed. This arrangement, along with intracluster π···π interactions and intercluster C─H···F─C interactions, contributes to the enhanced stability of [Cu41(SC6H3F2)15Cl3(P(PhF)3)6(H)25]2−. The presence, number, and location of hydrides within the nanocluster are established through a combination of experimental and density functional theory investigations. Notably, the addition of a phosphine ligand triggers a fascinating nanocluster‐to‐nanocluster transformation in [Cu41(SC6H3F2)15Cl3(P(PhF)3)6(H)25]2−, resulting in the generation of two nanoclusters, [Cu14(SC6H3F2)3(PPh3)8H10]+ and [Cu13(SC6H3F2)3(P(PhF)3)7H10]0. Furthermore, it is demonstrated that [Cu41(SC6H3F2)15Cl3(P(PhF)3)6(H)25]2− exhibits catalytic activity in the hydrogenation of nitroarenes. This intriguing nanocluster provides a unique opportunity to explore the assembly of M13 units, similar to other coinage metal nanoclusters, and investigate the nanocluster‐to‐nanocluster transformation in phosphine and thiol ligand co‐protected copper nanoclusters. [ABSTRACT FROM AUTHOR]

The nature of (imide)N–X⋯N(pyridine) halogen‐bonded complexes formed by six N‐haloimides and sixteen 2‐substituted pyridines are studied using X‐ray crystallography (68 crystal structures), Density Functional Theory (DFT) (86 complexation energies), and NMR spectroscopy (90 association constants). Strong halogen bond (XB) donors such as N‐iodosuccinimide form only 1:1 haloimide:pyridine crystalline complexes, but even stronger N‐iodosaccharin forms 1:1 haloimide:pyridine and three other distinct complexes. In 1:1 haloimide:pyridine crystalline complexes, the haloimide's N─X bond exhibits an unusual bond bending feature that is larger for stronger N‐haloimides. DFT complexation energies (ΔEXB) for iodoimide–pyridine complexes range from −44 to −99 kJ mol−1, while for N‐bromoimide–pyridine, they are between −31 and −77 kJ mol−1. The ΔEXB of I⋯N XBs in 1:1 iodosaccharin:pyridine complexes are the largest of their kind, but they are substantially smaller than those in [bis(saccharinato)iodine(I)]pyridinium salts (−576 kJ mol−1), formed by N‐iodosaccharin and pyridines. The NMR association constants and ΔEXB energies of 1:1 haloimide:pyridine complexes do not correlate as these complexes in solution are heavily influenced by secondary interactions, which DFT studies do not account for. Association constants follow the σ‐hole strengths of N‐haloimides, which agree with DFT and crystallography data. The haloimide:2‐(N,N‐dimethylamino)pyridine complex undergoes a halogenation reaction resulting in 5‐iodo‐2‐dimethylaminopyridine. [ABSTRACT FROM AUTHOR]

Vitrimers are an innovative class of polymers that boast a remarkable fusion of mechanical and dynamic features, complemented by the added benefit of end‐of‐life recyclability. This extraordinary blend of properties makes them highly attractive for a variety of applications, such as the automotive sector, soft robotics, and the aerospace industry. At their core, vitrimer materials consist of crosslinked covalent networks that have the ability to dynamically reorganize in response to external factors, including temperature changes, pressure variations, or shifts in pH levels. In this review, the aim is to delve into the latest advancements in the theoretical understanding and computational design of vitrimers. The review begins by offering an overview of the fundamental principles that underlie the behavior of these materials, encompassing their structures, dynamic behavior, and reaction mechanisms. Subsequently, recent progress in the computational design of vitrimers is explored, with a focus on the employment of molecular dynamics (MD)/Monte Carlo (MC) simulations and density functional theory (DFT) calculations. Last, the existing challenges and prospective directions for this field are critically analyzed, emphasizing the necessity for additional theoretical and computational advancements, coupled with experimental validation. [ABSTRACT FROM AUTHOR]

The possibility to engineer (GeTe)m(Sb2Te3)n phase‐change materials to co‐host ferroelectricity is extremely attractive. The combination of these functionalities holds great technological impact, potentially enabling the design of novel multifunctional devices. Here an experimental and theoretical study of epitaxial (GeTe)m(Sb2Te3)n with GeTe‐rich composition is presented. These layered films feature a tunable distribution of (GeTe)m(Sb2Te3)1 blocks of different sizes. Breakthrough evidence of ferroelectric displacement in thick (GeTe)m(Sb2Te3)1 lamellae is provided. The density functional theory calculations suggest the formation of a tilted (GeTe)m slab sandwiched in GeTe‐rich blocks. That is, the net ferroelectric polarization is confined almost in‐plane, representing an unprecedented case between 2D and bulk ferroelectric materials. The ferroelectric behavior is confirmed by piezoresponse force microscopy and electroresistive measurements. The resilience of the quasi van der Waals character of the films, regardless of their composition, is also demonstrated. Hence, the material developed hereby gathers in a unique 2D platform the phase‐change and ferroelectric switching properties, paving the way for the conception of innovative device architectures. [ABSTRACT FROM AUTHOR]