Symmetry related proton conductivity tunability via aliovalent metal substitution in imidazolium templated stable metal-organic framework hybrid membranes.

Proton-conducting materials have gained popularity owing to their extensive applications in biologic/chemical sensors, supercapacitors, proton sieving, and proton-exchange-membrane fuel cells. To date, the most commercially used polymer membrane has been the Nafion series that exhibits conductivity exceeding 0.1 S cm, however, this series is expensive, has poor dimensional stability, and requires a complex synthesis process.

Two α-SiO-Related Deep-Ultraviolet Phase-Matchable Optical Nonlinear Beryllium Silicate Crystals NaBeSiO and LiBeSiO with Enhanced SHG Effect.

Deep-UV, (wavelength λ < 200 nm) nonlinear-optical (NLO) silicate crystals have long been troubled by weak second-harmonic-generation (SHG) effect and common non-phase-matchability, leading to the stagnation of silicate research, despite abundant reserves of silicates on the earth. Representative and simple α-SiO is an ideal structural prototype toward improving silicate NLO performance by exploring efficient strategies. Herein, through two-step structural modulations based on fundamental "distortion and superposition" principles of NLO response, two deep-UV NLO crystals taking α-SiO as a structural template, NaBeSiO and LiBeSiO, are synthesized successively.

Promoting structural distortion to enhance the crystal field strength of Mn(II) in tetrahedral bromide for near-unity yellow emission.

Two zero-dimensional hybrid manganese bromide polymorphs ((DMAPH)MnBr) exhibit single-crystal to single-crystal phase transformation, accompanied by an increase in MnBr tetrahedral bond angle variance (). This structural change leads to an emission redshift due to enhanced crystal field strength, achieving yellow emission with near-unity quantum yield, which highlights its potential for solid-state lighting applications.

Optical activity levels of metal centers controlling multi-mode emissions in low-dimensional hybrid metal halides for anti-counterfeiting and information encryption.

In-depth insight into the electronic competition principles between inorganic units and organic ligands proves to be extremely challenging for controlling multi-mode emissions in low-dimensional hybrid metal halides (LHMHs). Herein, an efficient blue emission from organic ligand was engineered in (DppyH)MCl (Dppy = diphenyl-2-pyridylphosphine, M = Zn, Cd) due to the reverse type I band alignment constructed by optically inert units with nd shell electrons. By contrast, the optically active [MnCl] with semi-fully filled 3d shell electrons prompts the band alignment of type II, resulting in the narrowband green emission of Mn, along with an energy transfer from DppyH to [MnCl].

Relaxed stability criteria of delayed neural networks using delay-parameters-dependent slack matrices.

This note aims to reduce the conservatism of stability criteria for neural networks with time-varying delay. To this goal, on the one hand, we construct an augmented Lyapunov-Krasovskii functional (LKF), incorporating some delay-product terms that capture more information about neural states. On the other hand, when dealing with the derivative of the LKF, we introduce several parameter-dependent slack matrices into an affine integral inequality, zero equations, and the S-procedure.

Photocatalyst Au@Ni-MOFs with Different Plasmonic Coverages for Improved Hydrogen Evolution from Water.

Plasmonic materials are fundamental photosensitizer materials for photocatalytic reactions. Various structures, including core-shell types, satellite types, and distribution types, have been designed and prepared for the optimization of photocatalytic reactions. However, understanding the profound enhancement mechanism of various structures is still challenging.

PbBeBO: A High-Performance Ultraviolet Nonlinear-Optical Crystal with Functional [BeBO] Group.

High-performance nonlinear-optical (NLO) crystals need to simultaneously meet multiple basic and conflicting performance requirements. Here, by using a partial chemical substitution strategy, the first noncentrosymmetric (NCS) PbBeBO crystal with a BeBO group was synthesized, exhibiting a two-dimensional [BeBO] layer constructed by interconnecting BeBO groups and bridged PbO with an active lone pair. The crystal shows a promising UV NLO functional feature, including a strong SHG effect of 3.

Metavalently bonded tellurides: the essence of improved thermoelectric performance in elemental Te.

Elemental Te is important for semiconductor applications including thermoelectric energy conversion. Introducing dopants such as As, Sb, and Bi has been proven critical for improving its thermoelectric performance. However, the remarkably low solubility of these elements in Te raises questions about the mechanism with which these dopants can improve the thermoelectric properties.

Visible-light-promoted regioselective hydrocarboxylation of allenes with formate salt and CO.

Visible-light-promoted hydrocarboxylation of allenes with formate salt and CO was developed for the first time using commercially available [Ir(ppy)(dtbbpy)]PF as a photocatalyst. This strategy provides an efficient and practical method to access β,γ-unsaturated linear carboxylic acids in moderate yields with complete regioselectivity.

A 66-Nuclear All-Alkynyl Protected Peanut-Shaped Silver(I)/Copper(I) Heterometallic Nanocluster: Intermediate in Copper-Catalyzed Alkyne-Azide Cycloaddition.

Ligand-protected heterometallic nanoclusters in contrast to homo-metal counterparts show more broad applications due to the synergistic effect of hetero-metals but their controllable syntheses remain a challenge. Among heterometallic nanoclusters, monovalent Ag-Cu compounds are rarely explored due to much difference of Ag(I) and Cu(I) such as atom radius, coordination habits, and redox potential. Encouraged by copper-catalyzed alkyne-azide cycloaddition (CuAAC) reaction, comproportionation reaction of Cu(II)X and Cu(0) in the presence of (PhC≡CAg) complex and molybdate generated a core-shell peanut-shaped 66-nuclear Ag(I)-Cu(I) heterometallic nanocluster, [(MoO)@CuAg(PhC≡C)] (referred to as AgCu).

Cocrystallization-driven Formation of fcc-based Ag Nanocluster with Chinese Triple Luban Lock Shape.

Luban locks with mortise and tenon structure have structural diversity and architectural stability, and it is extremely challenging to synthesize Luban lock-like structures at the molecular level. In this work, we report the cocrystallization of two structurally related atom-precise fcc silver nanoclusters Ag (SPhF) (PPh ) (Ag ) and Ag (μ -S)(SPhF) (PPh ) (Ag ). It is worth noting that the Ag cluster is the first compound to simulate the complex Luban lock structure at the molecular level.

Surface defect-engineered Fe doping in layered Co-based complex as highly efficient bifunctional electrocatalysts for overall water splitting.

The electrocatalytic splitting of water to produce hydrogen is regarded as an efficient and promising strategy but is limited by its large overpotential; thus, a highly efficient electrocatalyst is urgently needed. Mixed metal doping is an important strategy in defect engineering because the heteroatoms can change the intrinsic structure to form defects by affecting the atomic coordination mode and adjusting the electronic structure, which is often accompanied by morphological changes. Herein, two-dimensional layered bimetallic Co-pydc containing axially coordinated water molecules was selected by producing surface defects through Fe doping in Co centers as bifunctional electrocatalysts for OER and HER.

Stereochemically Active Lone-Pair Containing Metal Substitution in Polar Axis toward a Giant Phase-Matchable Optical Nonlinear Silicate Crystal Li(OH)PbSiO.

Atoms in special lattice sites can play a crucial role in realizing materials properties, which is long pursued but difficult to control. Herein, by adopting a stereochemically active lone-pair-containing metal substitution strategy, a nonlinear-optical (NLO) silicate crystal Li(OH)PbSiO was successfully synthesized, featuring [PbSiO] layers with the perfect orientation of the stereochemically active lone-pair Pb(II) cation in the polar-axis lattice. Li(OH)PbSiO overcomes the long-standing problem of silicates, that is, poor nonlinear properties because it exhibits both the largest birefringence of 0.

Tuning Binding Strength of Multiple Intermediates towards Efficient pH-universal Electrocatalytic Hydrogen Evolution by Mo O -NbN O Heterocatalysts.

Developing efficient and robust hydrogen evolution reaction (HER) catalysts for scalable and sustainable hydrogen production through electrochemical water splitting is strategic and challenging. Herein, heterogeneous Mo O -NbN O supported on N-doped graphene (defined as Mo O -NbN O /NG) is synthesized by controllable hydrothermal reaction and nitridation process. The O-exposed Mo O clusters covalently confined on NbN O nanodomains provide a distinctive interface configuration and appropriate electronic structure, where fully exposed multiple active sites give excellent HER performance beyond commercial Pt/C catalyst in pH-universal electrolytes.

Photochemical Synthesis of Atomically Precise Ag Nanoclusters.

Photochemical methods are effective for controllable synthesis of silver nanoparticles with specific sizes and shapes. Whether they are capable of fabricating Ag nanoclusters (NCs) with atomic precision is yet to be proved. In this work, we synthesize an atomically precise Ag NC, [Ag(4-MePhC≡C)(Dpppe)](SbF) (), a process mediated by visible light.

Selective Photochromic Response to Low-Dose X-ray Radiation Detection in One-Dimensional Cadmium-Viologen Complexes.

Photochromic viologen-based materials have emerged as one of the most promising candidates for the development of X-ray light detection applications, including medical diagnosis and treatment, environmental radiation inspection, and industrial crack detection. However, the design and construction of low-dose X-ray-sensitive complexes remains an immense challenge, especially for the in-depth dissection of their response mechanisms. Herein, by using ,'-4,4'-bipyridiniodipropionate (CV) as functional sensitive structural units and cadmium as heavy atoms, two cadmium-viologen complexes with one-dimensional chained structures, namely, [CdCl(CV)(HO)] () and [CdBr(CV)] (), have been constructed, which exhibit a remarkable and selective photochromic response to low-dose X-ray radiation detection.

Entropy-Driven Ultrafast Ion Conduction Via Confining Organic Plastic Crystals in Ordered Nanochannels of Covalent Organic Frameworks.

Low conductivity over a wide temperature region due to ultra-slow ion migration dynamics is a key issue in the field of solid-state electrolytes (SSE), which needs to be solved and improved. Covalent organic frameworks (COFs), a rapidly growing class of porous crystalline materials, emerge as a new research hotspot in the field of SSEs. This is due to their homogeneously dispersed sites and well-defined pathways for ion diffusion, demonstrating great advantages over conventional non-porous solids.

Water induced ultrathin MoC nanosheets with high-density grain boundaries for enhanced hydrogen evolution.

Grain boundary controlling is an effective approach for manipulating the electronic structure of electrocatalysts to improve their hydrogen evolution reaction performance. However, probing the direct effect of grain boundaries as highly active catalytic hot spots is very challenging. Herein, we demonstrate a general water-assisted carbothermal reaction strategy for the construction of ultrathin MoC nanosheets with high-density grain boundaries supported on N-doped graphene.

Blue Light-Excitable Broadband Yellow Emission in a Zero-Dimensional Hybrid Bismuth Halide with Type-II Band Alignment.

Zero-dimensional (0D) organic-inorganic hybrid metal halides have captured broad interest in the lighting and display fields because of their unique electronic structures and splendid broadband emission properties. However, the blue light-excitable broadband yellow emissions have been rarely reported in 0D hybrid metal halides. Here, we design a new 0D bismuth hybrid, (4cmpyH)BiCl (, 4cmpy = 4-(chloromethyl)pyridine), featuring isolated edge-sharing bioctahedral [BiCl] dimers surrounded by rigid, conjugated, and luminescent organic [4cmpyH] cations.

PbBeBO: an ultraviolet nonlinear-optical crystal with unprecedented π-π interacting BeBO group.

π-Conjugated-group systems are fascinating and have been pursued for nonlinear materials owing to their superior optical and electronic properties, but are so far quite limited. Here, we report a new ultraviolet (UV) nonlinear-optical (NLO) beryllium borate crystal PbBeBO that manifests an unprecedented π-π interacting BeBO group, constructed by interconnected π-conjugated BeO and BO units. The PbBeBO crystal has a short UV cutoff wavelength of 249 nm, phase-matching behavior in the whole transmission region from UV to IR light region (249-3166 nm), and remarkably the largest NLO effect (18.

Ligand Engineering Triggered Efficiency Tunable Emission in Zero-Dimensional Manganese Hybrids for White Light-Emitting Diodes.

Zero-dimensional (0D) hybrid manganese halides have emerged as promising platforms for the white light-emitting diodes (-LEDs) owing to their excellent optical properties. Necessary for researching on the structure-activity relationship of photoluminescence (PL), the novel manganese bromides (CHN)MnBr and (CHN)MnBr are reported by screening two ligands with similar atomic arrangements but various steric configurations. It is found that (CHN)MnBr with planar configuration tends to promote a stronger electron-phonon coupling, crystal filed effect and concentration-quenching effect than (CHN)MnBr with chair configuration, resulting in the broadband emission (FWHM = 63 nm) to peak at 539 nm with a large Stokes shift (70 nm) and a relatively low photoluminescence quantum yield (PLQY) (46.

PbBi(SeO)F and PbBi(SeO)Cl: Coexistence of Three Kinds of Stereochemically Active Lone-Pair Cations Exhibiting Excellent Nonlinear Optical Properties.

Stereochemically active lone-pair (SCALP) cations are one attractive type of nonlinear optical (NLO)-active units because of their large microcosmic polarizability and anisotropy. Currently, the single and/or dual lone-pair cation-based noncentrosymmetric (NCS) oxides have been extensively investigated and verified to be one class of outstanding NLO materials. From the perspective of function optimization, the integration of three kinds of SCALP cations into one crystal may synergistically improve the NLO properties, which is greatly expected but unexplored to date.

Role of Au-Sn bonding for stabilizing a gold nanocatalyst: a reinvestigation of purple of Cassius.

Purple of Cassius is a pigment based on a gold colloid that has been known for hundreds of years. It has had a profound influence on modern nanoscience. But the origin of the small size of the Au nanoparticles (NPs) and their superior stability remains ambiguous.

Fast Hydroxide Conduction via Hydrogen-Bonding Network Confined in Benzimidazolium-Functionalized Covalent Organic Frameworks.

In both hydrophobic and hydrophilic nanochannels, confined water clusters spontaneously form dense internal hydrogen bond networks and hence exhibit fast mass-transfer kinetics. Covalent organic frameworks (COFs), a porous polymer, enables one-dimensional open channels to achieve ordered assembly guided by synthetic techniques and allows the accommodation of a large number of water molecules within the nanochannels. In the field of alkaline anion exchange membrane fuel cells, it has been a long-term pursuit of scientists to build abundant hydrogen bonds around hydrogen oxides (OH) to improve the conduction of OH by increasing the water content.