A Hollowed-Out Heterometallic Cluster for Catalytic Knoevenagel Condensation.

Lanthanide-containing clusters are synthetically challenging and with significant chemical and materials applications. Herein, two isostructural heterometallic clusters of the formula (NO)@[LnNi(OH)(IDA)(CHCOO)(NO)(HO)]Cl⋅xHO⋅yCHOH (IDA=iminodiacetate; Ln=Gd 1, x=110, y=0; Ln=Eu 2, x=95, y=40) were obtained via co-hydrolysis of Ln (Gd or Eu) and Ni in the presence of iminodiacetate (IDA). Crystallographic studies show that each features a truncated tetrahedral core of LnNi within which a void of 1.

Enhancing Effect of Fullerene Guest and Counterion on the Structural Stability and Electrical Conductivity of Octahedral Metallo-Supramolecular Cages.

Metallo-supramolecular cages have garnered tremendous attention for their diverse yet molecular-level precision structures. However, the physical properties of these supramolecular ensembles, which are of potential significance in molecular electronics, remain largely unexplored. We herein constructed a series of octahedral metallo-cages and cage-fullerene complexes with notably enhanced structural stability.

Ln Induced Thermally Activated Delayed Fluorescence of Chiral Heterometallic Clusters LnAg.

A series of TADF-active compounds: 0D chiral Ln-Ag(I) clusters L-/D-LnAg-0D (Ln=Eu/Gd) and 2D chiral Ln-Ag(I) cluster-based frameworks L-/D-LnAg-2D (Ln=Gd) has been synthesized. Atomic-level structural analysis showed that the chiral Ag(I) cluster units {AgS} in L-/D-LnAg-0D and L-/D-LnAg-2D exhibited similar configurations, linked by varying numbers of [Ln(HO)] (x=6 for 0D, x=3 for 2D) to form the final target compounds. Temperature-dependent emission spectra and decay lifetimes measurement demonstrated the presence of TADF in L-LnAg-0D (Ln=Eu/Gd) and L-GdAg-2D.

Accurate Prediction of the Magnetic Ordering Temperature of Ultralow-Temperature Magnetic Refrigerants.

Adiabatic demagnetization refrigeration is known to be the only cryogenic refrigeration technology that can achieve ultralow temperatures (≪1 K) at gravity-free conditions. The key indexes to evaluate the performance of magnetic refrigerants are their magnetic entropy changes (-Δ) and magnetic ordering temperature (). Although, based on the factors affecting the -Δ of magnetic refrigerants, one has been able to judge if a magnetic refrigerant has a large -Δ, how to accurately predict their remains a huge challenge due to the fact that the of magnetic refrigerants is related to not only magnetic exchange but also single-ion anisotropy and magnetic dipole interaction.

Magnetic Order Transition of a Two-Dimensional Square-Lattice Electrocatalyst Assembled by Fe-N Units: Crucial Role on Oxygen Reduction.

Herein, we theoretically investigate the effect of magnetic orders on electrocatalytic oxygen reduction reaction (ORR) properties on the Fe-N site-embedded two-dimensional (2D) covalent organic framework (Fe-N@COF-CN) under realistic environments. The Fe-N@COF-CN shows a 2D square-lattice (sql) topology with three magnetic order states: one ferromagnetic state (FM) and two antiferromagnetic states (AFM1 and AFM2). Specially, the electrocatalyst in the AFM2 state shows a remarkable onset potential of 0.

Tuning Electrocatalytic Water Oxidation Activity: Insights from the Active-Site Distance in LnCu Clusters.

Atomically precise metal clusters serve as a unique model for unraveling the intricate mechanism of the catalytic reaction and exploring the complex relationship between structure and activity. Herein, three series of water-soluble heterometallic clusters LnCu, abbreviated as LnCu-AC (Ln = La, Nd, Gd, Er, Yb; HAC = acetic acid), LnCu-IM (Ln = La and Nd; IM = Imidazole), and LnCu-IDA (Ln = Nd; HIDA = Iminodiacetic acid) are presented, each featuring a uniform metallic core stabilized by distinct protected ligands. Crystal structure analysis reveals a triangular prism topology formed by six Cu ions around one Ln ion in LnCu, with variations in Cu···Cu distances attributed to different ligands.

Conductive Lanthanide Metal-Organic Frameworks with Exceptionally High Stability.

Electrically conductive metal-organic frameworks (MOFs) have been extensively studied for their potential uses in energy-related technologies and sensors. However, achieving that goal requires MOFs to be highly stable and maintain their conductivity under practical operating conditions with varying solution environments and temperatures. Herein, we have designed and synthesized a new series of {[Ln(μ-O)(μ-OH)(INA)(GA)](CFSO)(HO)} (denoted as , Ln = Gd, Tm, and Lu, INA = isonicotinic acid, GA = glycolic acid) single crystals, where electrons are found to transport along the π-π stacked aromatic carbon rings in the crystals.

Correlation of the spin state and catalytic property of M-N single-atom catalysts in oxygen reduction reactions.

The rational design of high-performance catalysts for oxygen reduction reactions (ORRs) is of great importance for large-scale applications in the field of proton-exchange membrane fuel cells and the green synthesis of HO. The effect of spin states of paramagnetic metal ions on the selectivity of ORRs is significant for single-atom catalysts (SACs). In this work, spin-polarization density functional theory (DFT) calculations, we systematically investigated the popular paramagnetic metal-nitrogen graphene (M-N-C, M = Mn, Fe, and Co) SACs to mainly focus on the correlation of spin states and catalytic performance ( activity and selectivity).

Rational design of bimetallic MXene solid solution with High-Performance electrocatalytic N reduction.

Electrocatalytic N reduction reaction (eNRR) was an effective alternative method for green synthesis of NH. By combining the first-principal Density functional theory (DFT) calculations and Monte Carlo (MC) simulation, we systematacially investigated 24 types equal-ratio bimetallic MXene solid solution, involving 88 different catalysts. Our focus was on the catalytic performance of these materials in eNRR.

Magnetic and Dielectric Switchings Actuated by the Rotation of the Picoline Ligand in an Iron-Based Dinuclear Phase-Transition Complex.

Multifunctional materials with switchable magnetic and dielectric properties are crucial for the development of memory and sensor devices. Herein, we report a methoxy-bridged dinuclear iron-pyridyl complex [Fe(4-picoline)(NCS)(μ-OCH)] (), which shows simultaneous thermal-induced magnetic and dielectric switchings. Within the phase-transition temperature range, both magnetic switching and the dielectric anomaly were detected, in which the thermal hysteresis loops were 23 and 21 K, respectively.

Co-Dissolved Isostructural Polyoxovanadates to Construct Single-Atom-Site Catalysts for Efficient CO Photoreduction.

We explored a co-dissolved strategy to embed mono-dispersed Pt center into V O support via dissolving [PtV O ] into [V O ] aqueous solution. The uniform dispersion of [PtV O ] in [V O ] solution allows [PtV O ] to be surrounded by [V O ] clusters via a freeze-drying process. The V centers in both [PtV O ] and [V O ] were converted into V O via a calcination process to stabilize Pt center.

Construction of a High Nuclear Gadolinium Cluster with Enhanced Magnetocaloric Effect through Structural Transition.

Starting from a dinuclear complex {Gd(L)(NO)(HO)}·2(CHCN) () based on 2,6-dimethoxyphenol (HL), a nonanuclear cluster {Gd(L)(μ-OH)(μ-OH)(μ-OCH)(NO) (HO)}(OH)·2HO () was obtained via modulating the amount of the ligand and base. Both of them have been structurally and magnetically characterized. Complex decorates the Gd core bridged by double μ-phenoxyl oxygen atoms and coordinated neutral CHCN molecules, while features the Gd core with a sandglass-like topology.

W Single-Atom Catalyst for CH Photooxidation in Water Vapor.

Solar-driven high-efficiency and direct conversion of methane into high-value-added liquid oxygenates against overoxidation remains a great challenge. Herein, facile and mass fabrication of low-cost tungsten single-atom photocatalysts is achieved by directly calcining urea and sodium tungstate under atmosphere (W-SA-PCN-m, urea amount m = 7.5, 15, 30, and 150 g).

Family of Nanoclusters, Ln (Ln = Sm/Eu) and Gd, Exhibiting Magnetocaloric Effects and Fluorescence Sensing for MnO.

A family of nanoclusters, [Ln(EDTA)(OAc)(CO)(μ-OH)(μ-OH)(HO)]·OAc·HO ( ≈ 50, Ln = Sm for ; ≈ 70, Ln = Eu for ) and [Gd(EDTA)(OAc)(CO)(CO)(μ-OH)(μ-OH)(HO)]·(HO) ( ≈ 70 for ; HEDTA = ethylene diamine tetraacetic acid), was prepared through the assembly of repeating subunits under the action of an anion template. The analysis of the structures showed that compounds and containing 33 Ln ions were isostructural, which were constructed by three kinds of subunits in the presence of CO as an anion template, while compound had a slightly different structure. Compound containing 32 Gd ions was formed by three types of subunits in the presence of CO and CO as a mixed anion template.

A new family of decanuclear LnCr clusters exhibiting a magnetocaloric effect.

Two dimeric Ln-Cr clusters with formula {Ln(HO)[LnCr(L)(CHCOO)(μ-OH)(HO)]}·(ClO)·HO (Ln = Gd, = 35 for 1 and Ln = Dy, = 45 for 2, HL = 2-pyrazinecarboxylic acid) were obtained by a ligand-controlled hydrolytic method with a mixed ligand system (2-pyrazinecarboxylic acid and acetate). Single crystal structure analysis showed that two trigonal bipyramids of [GdCr(μ-OH)] worked as building blocks in constructing the metal-oxo cluster core of [GdCr(μ-OH)] by sharing a common top - a Cr ion. Additionally, compound 1 forms a three-dimensional framework with a one-dimensional nanopore channel along the -axis through a hydrogen-bond interaction between the cationic cluster core and the free mononuclear cation [Gd(HO)] and the π-bond interactions of the pyrazine groups on the two cationic cluster cores.

Nuclearity enlargement from [PWO@Ag] to [(PWO)@Ag] and 2D and 3D network formation driven by bipyridines.

The structural transformations of metal nanoclusters are typically quite complex processes involving the formation and breakage of several bonds, and thus are challenging to study. Herein, we report a case where two lacunary Keggin polyoxometallate templated silver single-pods [PWO@Ag] (SD/Ag51b) fuse to a double-pod [(PWO)@Ag] by reacting with 4,4'-bipyridine (bipy) or 1,4-bis(4-pyridinylmethyl)piperazine (pi-bipy). Their crystal structures reveal the formation of a 2D 4-sql layer (SD/Ag72a) with bipy and a 3D pcu framework (SD/Ag72c) with pi-bipy.

The synergetic effect of an aqua ligand and metal site on the performance of single-atom catalysts in HO synthesis: a density functional theory study.

Studying the effect of the coordination field on the catalytic property is critical for the rational design of outstanding electrocatalysts for HO synthesis. Herein, via density functional theory (DFT) calculations and ab initio molecular dynamic (AIMD) simulations, we built an effective computational framework to identify the synergetic effect of an aqua ligand and metal ion on the 2e ORR catalytic performance under gas condition and aqua solvent. Specifically, the screening results of 29 single-atom catalysts (SACs), TM@CN (TM = transition metal), indicated that Cu@CN features excellent catalytic property with thermal stability, lowest 2e ORR overpotential (0.

Tuning the (Chir)Optical Properties and Squeezing out the Inherent Chirality in Polyphenylene-Locked Helical Carbon Nanorings.

Distorting linear polyaromatic hydrocarbons (PAHs) out of planarity affects their physical properties and breaks their symmetry to induce inherent chirality. However, the chirality cannot be achieved in large distorted PAHs-based macrocycles due to a low racemization barrier for isomerization. Herein, we report the precise synthesis and tuning size-dependent (chir)optical properties of a new class of chiral PAHs-containing conjugated macrocycles (cyclo[n]paraphenylene-2,6-anthrylene, [n]CPPAn ; n=6-8).

Integration of bio-inspired lanthanide-transition metal cluster and P-doped carbon nitride for efficient photocatalytic overall water splitting.

Photosynthesis in nature uses the MnCaO cluster as the oxygen-evolving center to catalyze the water oxidation efficiently in photosystem II. Herein, we demonstrate bio-inspired heterometallic LnCo (Ln = Nd, Eu and Ce) clusters, which can be viewed as synthetic analogs of the CaMnO cluster. Anchoring LnCo on phosphorus-doped graphitic carbon nitrides (PCN) shows efficient overall water splitting without any sacrificial reagents.

Enantioselective Recognition and Separation of Symmetric Substances via Chiral Metal-Organic Frameworks.

A promising route toward the enantioselective recognition and separation of racemic molecules is the design of chiral metal-organic frameworks (CMOFs) with high enantioselectivity and stability. Herein, we report porous CMOFs Δ- and Λ-RuEu-MOFs constructed from the -symmetry helical chiral Ru(phen)-derived tricarboxylate ligand and Eu units, which can be utilized as adsorbents for the enantioselective recognition and separation of 1,1'-bi-2-naphthol (BINOL) derivatives. Investigation of the circular dichroism enantiodifferentiation between the host and guest suggested that Δ- and Λ-RuEu-MOFs can be employed as chiral sensors to discriminate axial enantiomers due to their diastereomeric host-guest relationship.