High-Nuclearity LnAl Clusters: Neonates of Open Hollow Dodecahedral Cage Families.

Open hollow dodecahedral cage clusters have long been a coveted target in synthetic chemistry, yet their creation poses immense challenges. Here we report two open hollow dodecahedral lanthanide-aluminum (Ln-Al) heterometallic cage clusters, namely, [LnAl(μ-OH)(μ-OH)(OAc)(HO)](ClO)·(MeCN)·(HO), (Ln = Dy and = 27, = 300 for ; Ln = Y and = 28, = 420 for ). Remarkably, the 350 metal atoms in and display a Keplerate-type four-shell structure of truncated icosidodecahedron@dodecahedron@dodecahedron@icosidodecahedron.

Achieving Magnetic Refrigerants with Large Magnetic Entropy Changes and Low Magnetic Ordering Temperatures.

Adiabatic demagnetization refrigeration (ADR) is a promising cooling technology with high efficiency and exceptional stability in achieving ultralow temperatures, playing an indispensable role at the forefront of fundamental and applied science. However, a significant challenge for ADR is that existing magnetic refrigerants struggle to concurrently achieve low magnetic ordering temperatures () and substantial magnetic entropy changes (-Δ) at ultralow temperatures. In this work, we propose the combination of Gd and Yb to effectively regulate both -Δ and in ultralow temperatures.

pH-Driven Rotational Configuration of Keggin-Fe Clusters and Their Transformations.

Keggin-Fe clusters are considered foundational building blocks or prenucleation precursors of ferrihydrite. Understanding the factors that influence the rotational configuration of these clusters, and their transformations in water, is vital for comprehending the formation mechanism of ferrihydrite. Here, we report syntheses and crystal structures of four lanthanide-iron-oxo clusters, namely, [DyFe(Gly)(μ-OH)(μ-OH)(μ-O)(HO)]·13ClO·19HO (), [DyFe(Gly)(μ-OH)(μ-O)(HO)]·13ClO·14HO (), [PrFe(Gly)(μ-OH)(μ-O)(μ-O)(HO)]·6ClO·20HO (), and [PrFe(Gly)(μ-OH)(μ-O)(HO)]·13ClO·22HO (, Gly = glycine).

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.

A Doped Lanthanide-Based Coordination Polymer Exhibiting High Relative Sensitivity to Ratiometric Luminescent Thermometers at 440 K.

Ratiometric luminescent thermometers with excellent performance often require the luminescent materials to possess high thermal stability and relative sensitivity (). However, such luminescent materials are very rare, especially in physiological (298-323 K) and high-temperature (>373 K) regions. Here we report the synthesis and luminescent property of [TbEu(pfbz)(phen)Cl] (), which not only exhibits high in physiological temperature but also has a up to 7.

Gd(OH)F: A Promising Cryogenic Magnetic Refrigerant.

Magnetic refrigerants with a large magnetocaloric effect (MCE) in a wide temperature range and low magnetic ordering temperature () in the sub-kelvin temperature region are not only crucial for adiabatic demagnetization refrigeration but also open up a broader parameter space for the optimal design of adiabatic demagnetization refrigerators. However, such magnetic refrigerants are extremely rare because they require magnetic materials to simultaneously satisfy three conditions: low , weak magnetic interaction, and high magnetic density. Here, we report the syntheses, heat capacities, and magnetic properties of Gd(OH)F (: = 1, : ≈ 1.

A Gd-based borate-carbonate framework exhibiting a large magnetocaloric effect at a low magnetic field.

A 3D borate-carbonate framework, GdB(OH)CO (1), was synthesized. Magnetic study reveals that its MCE is up to 33.5 J kg K at 2 K and 2 T, due to the introduction of a long magnetic exchange path of Gd-O-B-O-Gd leading to 1 exhibiting weak magnetic interaction.

Magnetocaloric Effect and Thermal Conductivity of a 3D Coordination Polymer of [Gd(HCOO)(CO)].

A 3D coordination polymer, [Gd(HCOO)(CO)] was prepared. Its magnetocaloric effect (MCE) (32.7 J K kg at 2 K and 2 T) is significantly larger than that of commercial GdGaO (GGG) (14.

Highly Thermostable and Efficient Formamidinium-Based Low-Dimensional Perovskite Solar Cells.

Currently, most two-dimensional (2D) metal halide perovskites are of the Ruddlesden-Popper type and contain the thermally unstable methylammonium (MA) molecules, which leads to inferior photovoltaic performance and mild stability. Here we report a new type of MA-free formamidinium (FA) based low-dimensional perovskites, featuring a general formula of (PDA)(FA) Pb I with propane-1,3-diammonium (PDA) as the organic spacer cation. The perovskite films with well-oriented crystal grains are attained under the assistance of the FACl additive, where the role of Cl is investigated through the grazing-incidence X-ray diffraction technique.

Lanthanide-Titanium Oxo Clusters as the Luminescence Sensor for Nitrobenzene Detection.

A luminescent lanthanide-titanium oxo cluster of EuTi(μ-O)(μ-O)(phen)(tbza)·4CHCN (, EuTi-phen-tbza, phen = 1,10-phenanthroline, Htbza = 4--butylbenzoic acid) was prepared through the reaction of phen, Htbza, Eu(Ac)·HO, and Ti(OPr) in acetonitrile. Its overall absolute quantum yield is 65.4% in solid state and 30.

Synthesis and Characterization of a Crown-Shaped 36-Molybdate Cluster and Application in Catalyzing Knoevenagel Condensation.

A novel crown-shaped 36-molybdate cluster with organophosphonate-functionalized polyoxomolybdates, (NH)NaH[Co(HO)TeMoO{N(CHPO)}]·42HO, has been successfully synthesized and well-characterized. It owns the highest nuclearity in the family of organophosphonate-based polyoxometalates reported so far. Furthermore, for the first time in the field, we illustrated that polyoxomolybdate could work as an effective heterogeneous catalyst for the Knoevenagel condensation reaction with high TOF (7714 h) and good recyclability.

36-Nuclearity Organophosphonate-Functionalized Polyoxomolybdates: Synthesis, Characterization and Selective Catalytic Oxidation of Sulfides.

The crown-shaped 36-molybdate cluster organophosphonate-functionalized polyoxomolybdates with the highest nuclearity in organophosphonate-based polyoxometalate chemistry, (NH ) Na H [Cu(H O)TeMo O {N(CH PO ) }] ⋅31 H O, has been reported for the first time. The synthesized 36-molybdate cluster was characterized by routine techniques and tested as a heterogeneous catalyst for selective oxidation of sulfides with impressive catalytic and selective performances after heat treatment. High efficiency (TON=15333) was achieved in the selective oxidation of sulfides to sulfoxides, caused by the synergic effect between copper and polyoxomolybdates and the generation of the cuprous species during the heat treatment.

Selenotungstates incorporating organophosphonate ligands and metal ions: synthesis, characterization, magnetism and catalytic efficiency in the Knoevenagel condensation reaction.

Three sandwich-type TM-containing (TM = transition metal) organophosphonate-based polyoxotungstate clusters, [TM(HO)(SeWO){Co(OOCCHNCHPO)}] (TM = Co, Ni), have been successfully synthesized, which are the first reported TM-containing organophosphonate-based selenotungstates. They were structurally characterized by PXRD analyses, IR spectroscopy, TGA analyses, etc. Magnetic measurements show that all three compounds exhibit antiferromagnetic interactions.

In Situ Observation of Vapor-Assisted 2D-3D Heterostructure Formation for Stable and Efficient Perovskite Solar Cells.

The heterogeneous stacking of a thin two-dimensional (2D) perovskite layer over the three-dimensional (3D) perovskite film creates a sophisticated architecture for perovskite solar cells (PSCs). It combines the remarkable thermal and environmental stabilities of 2D perovskites with the superior optoelectronic properties of 3D materials which resolves the chronic stability issue with no compromise on efficiency. Herein, we propose the vapor-assisted growth strategy to fabricate high-quality 2D/3D heterostructured perovskite films by introducing long-chain organoamine gases in which the 2D layers have a uniform and tunable thickness.

A New Organic Interlayer Spacer for Stable and Efficient 2D Ruddlesden-Popper Perovskite Solar Cells.

Two-dimensional (2D) perovskite materials have exhibited great possibilities toward the fabrication of highly efficient and stable solar cell devices. The large degree of structural versatility due to the viable choices of organic interlayer spacers promises new and valuable 2D perovskite species. Herein, phenyltrimethylammonium (PTA) is successfully employed as the organic interlayer spacer to prepare the 2D Ruddlesden-Popper perovskite films that exhibit exceptional optoelectronic properties.

A Stable Polyoxometalate-Based Metal-Organic Framework as Highly Efficient Heterogeneous Catalyst for Oxidation of Alcohols.

A novel copper-containing 3D polyoxometalate-based metal-organic framework (POMOF), H[CuCu(pzc)(pz){PWO}]·6HO (HENU-1, HENU = Henan University; Hpzc = pyrazine-2-carboxylic acid, pz = pyrazine), was successfully isolated by a one-step hydrothermal method. In this compound, the {PW} polyanion acts as a seven-connected linker bridging adjacent 2D double-layer networks, as well as a template to induce the formation of the desired 3D framework. Particularly, the pz ligands are generated from pzc ligands in situ during the reaction process.

Polyoxotungstate Cluster Species Connected by Glutamic Acid and Europium.

An organic-inorganic hybridized polyoxotungstate which contains two kinds of covalently linked tungstate clusters in its polyanion has been obtained. The three clusters are connected by glutamic acid molecules and europium atoms through Eu-O-C bonds. The cluster in the middle position is a tetramer.

Polyoxotungstates incorporated organophosphonate and nickel: synthesis, characterization and efficient catalysis for epoxidation of allylic alcohols.

Three new sandwich-type organophosphonate-functionalized polyoxotungstate clusters, [{Ni(H2O)5}x(AsW6O21)2{Ni(OOCCH2NCH2PO3)2}3] (x = 0 (Ni1), 1 (Ni2 and Ni3)), were successfully isolated via a "top-down" synthetic strategy. Compounds (Ni1-Ni3) were characterized by single crystal X-ray analysis, X-ray powder diffraction (XRPD), IR spectroscopy, UV-vis spectroscopy, and thermogravimetric analyses (TGA). Magnetic properties provide evidence for antiferromagnetic coupling in Ni2 and Ni3 and ferromagnetic interaction in Ni1.

Preparation, characterization, and catalytic performances of a pyrazine dicarboxylate-bridging rare-earth-containing polytungstoarsenate aggregate for selective oxidation of thiophenes and deep desulfurization of model fuels.

A new polytungstoarsenate, K6LiH6[Ce4(H2O)14(pzdc)(H2pzdc)As3W29O103]·22H2O (1) (H2pzdc = 2,3-pyrazinedicarboxylic acid), was synthesized via a conventional aqueous solution method. In this synthetic approach, the organic ligand pyrazine dicarboxylate acid was introduced into the arsenotungstate system. The synthesized compound 1 was well characterized using elemental analysis, IR spectroscopy, UV-vis spectroscopy, thermogravimetric analysis (TGA), powder X-ray diffraction (PXRD), and single-crystal X-ray diffraction.

A Crown-Shaped Ru-Substituted Arsenotungstate for Selective Oxidation of Sulfides with Hydrogen Peroxide.

An acetate-bridged Ru-substituted arsenotungstate [H N(CH ) ] [As W O {Ru (CH COO)} ]⋅22 H O (1) has been synthesized and structurally characterized. Four Ru atoms occupy the respective lacunary S2 sites of the crown-shaped polyanion [As W O ] , and each Ru atom is coordinated by one As atom and five μ -O atoms, comprising four from the S2 site and one from the acetate ligand. To the best of our knowledge, this coordination of the Ru atom, with an Ru-As bond length of 2.

A Novel Ruthenium-Decorating Polyoxomolybdate Cs₃Na₆H[MoRu₂O(OH)₂]·24H₂O: An Active Heterogeneous Oxidation Catalyst for Alcohols.

The first example of wholly inorganic ruthenium-containing polyoxomolybdate Cs₃Na₆H[MoRu₂O(OH)₂]·24H₂O () was isolated and systematically characterized by element analysis, infrared spectroscopy (IR), thermogravimetric analyses (TGA), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDX) and single-crystal X-ray diffraction. Compound is composed of an unprecedented {Mo}-type isopolymolybdate with a di-ruthenium core precisely encapsulated in its center, exhibiting a three-tiered ladder-like structure. The title compound can act as an efficient heterogeneous catalyst in the transformation of 1-phenylethanol to acetophenone.

In Situ Real-Time Study of the Dynamic Formation and Conversion Processes of Metal Halide Perovskite Films.

Metal halide perovskite solar cells (PSCs) have advanced to the forefront of solution-processed photovoltaic techniques and made stunning progress in power conversion efficiency (PCE). Further improvements in device performances rely on perfecting the structure and morphology of perovskite films. However, undesirable defects such as pinholes and grain boundaries are often created in film preparations due to lack of knowledge of the precise reaction mechanism.

Two New Sandwich-Type Polyoxomolybdates Functionalized with Diphosphonates: Efficient and Selective Oxidation of Sulfides to Sulfones.

Two sandwich-type polyoxomolybdates Na₈[MO₂{Mo₂O₅(O₃PCH₃C(O)PO₃)}₂] (M = Ni (); Co ()) were synthesized by one-pot reaction of Na₂HPMoO·14H₂O, 1-hydroxy ethidene diphosphonic acid (HEDP=HOC(CH₃)(PO₃H₂)₂), and (1) NiCl₂/CoCl₂ (2). Compounds and were characterized by single crystal X-ray analysis, X-ray powder diffraction (XRPD), IR spectroscopy, P NMR spectra, UV-vis spectroscopy, and thermogravimetric analyses (TGA). Structural analysis reveals that and exhibit similar centrosymmetric structure, which consists of one transition metal (TM) ion sandwiched by two same subunits {Mo₂O₅(O₃PCH₃C(O)PO₃)}.

Synthesis, characterization and catalytic epoxidation properties of lanthanide-stabilized peroxoisopolytungstates.

A series of new lanthanide-containing peroxoisopolyoxotungstates, KNa[H{Ln(WO)(HO)[WO(O)]}]·105HO [Ln = Ce (1), Nd (2), Sm (3), Tb (4), Er (5)], have been successfully synthesized and structurally characterized. All polyanions [Ln(WO)(HO){WO(O)}] are isostructural and consist of a central [Ln(WO)(HO)] cluster surrounded by four peripheral [WO(O)] units. They could act as efficient recyclable catalysts for the epoxidation of various alkenes including different cycloalkenes, styrene derivatives, internal and long-chain alkenes.