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The past decade has witnessed remarkable progress in cocrystal research, by virtue of the desires to address problematic properties of drugs. Notwithstanding the rapid advancements in knowledge-based cocrystal design, such as by leveraging different in silico virtual screening tools, obtaining false-positive results wherein predicted cocrystals fail to materialize experimentally remains a common occurrence. While being less disconcerting than the false-negative, there is a need to comprehend the underlying reasons as to why cocrystal formers bearing supramolecular features that indicate a high probability of cocrystallization would eventually fail. This enigma is associated with the thermodynamic instability of cocrystals or requirement of a high activation energy for cocrystallization, thus rendering them elusive under conventional production. This review aims to address this knowledge gap by providing a holistic overview on the strategic design and preparation of elusive cocrystals, followed by highlighting the importance of process control on the critical factors, such as reaction kinetics, the presence of catalysts, and annealing conditions. The challenges pertaining to the characterization and clinical translation of elusive cocrystals are also covered. Finally, an empirical analysis of the Cambridge Structural Database was conducted to explore the elusive cocrystal formation through understanding the differential cocrystallization behaviors among a series of isomers and structurally similar coformers. The insights gained herein offer scientists a guide for conducting cocrystal screening in a more rational and effective manner, with the ultimate goal of expediting the development of novel drug cocrystals for future clinical use. [ABSTRACT FROM AUTHOR]

Boron has been found to be able to form multiple bonds with lead. To probe Pb–B bonding, here we report an investigation of three Pb-doped boron clusters, PbB2−, PbB3O−, and PbB4O2−, which are produced by a laser ablation cluster source and characterized by photoelectron spectroscopy and ab initio calculations. The most stable structures of PbB2−, PbB3O−, and PbB4O2− are found to follow the formula, [PbB2(BO)n]− (n = 0–2), with zero, one, and two boronyl ligands coordinated to a triangular and aromatic PbB2 core, respectively. The PbB2− cluster contains a B＝B double bond and two Pb–B single bonds. The coordination of BO is observed to weaken Pb–B bonding but strengthen the B＝B bond in [PbB2(BO)n]− (n = 1, 2). The anionic [PbB2(BO)2]− and its corresponding neutral closed-shell [PbB2(BO)2] contain a B≡B triple bond. A low-lying Y-shaped isomer is also observed for PbB4O2−, consisting of a central sp2 hybridized B atom bonded to two boronyl ligands and a PbB unit. [ABSTRACT FROM AUTHOR]

Topological quasiparticles have garnered significant research attention in condensed matter physics. However, they are exceedingly rare in two-dimensional systems, particularly those hosting unconventional topological quasiparticles. In this work, employing first-principles calculations and symmetry analysis, we demonstrate that PtS, PtSe, and PtTe monolayers serve as high-quality two-dimensional topological semimetal materials. These materials exhibit multiple types of topological quasiparticles around the Fermi level in the absence of spin–orbit coupling, such as conventional linear Weyl points and unconventional quadratic Weyl points in the PtS monolayer, as well as nodal loops in PtSe and PtTe monolayers. When spin–orbit coupling (SOC) is introduced, a tiny gap opens, transforming the systems into quantum spin hall insulators. Simultaneously, three spin–orbit Dirac points, robust against SOC, appear at the X, Y, and M points. We illustrate the symmetry protection, low-energy effective model, and edge states of these topological states. Our work provides an excellent material platform for studying novel two-dimensional topological quasiparticles and topological insulators. [ABSTRACT FROM AUTHOR]

It is a major challenge to perform one-pot hydroxylation of benzene to phenol under mild conditions, which replaces the environmentally harmful cumene method. Thus, finding highly efficient heterogeneous catalysts that can be recycled is extremely significant. Herein, a (POM)-based hybrid compound {[FeII(pyim)2(C2H5O)][FeII(pyim)2(H2O)][PMo V2 Mo VI9 V IV3 O42]}·H2O (pyim = 2-(2-pyridyl)benzimidazole) (Fe2-PMo11V3) was successfully prepared by hydrothermal synthesis using typical Keggin POMs, iron ions and pyim ligands. Single-crystal diffraction shows that the Fe-pyim unit in Fe2-PMo11V3 forms a stable double-supported skeleton by Fe–O bonding to the polyacid anion. Remarkably, due to the introduction of vanadium, Fe2-PMo11V3 forms a divanadium-capped conformation. Benzene oxidation experiments indicated that Fe2-PMo11V3 can catalyze the benzene hydroxylation reaction to phenol in a mixed solution of acetonitrile and acetic acid containing H2O2 at 60 °C, affording a phenol yield of about 16.2% and a selectivity of about 94%. [ABSTRACT FROM AUTHOR]

The current traditional phenol production process has many shortcomings, and the efficient and clean photocatalytic one-step oxidation to phenol is gradually attracting attention. Heteropolyacids (PMo10V2) with high-density Lewis acid active sites and excellent photoelectron transfer ability are ideal choices for catalytic reactions. In this study, a copper-modified isolated dimeric hybrid nanocluster, [Cu(pyim)2]2[Cu(pyim)2(P2Mo VI20 Mo V2 V IV4 O82)]2·(H2O) (pyim = [2-(pyridin-2-yl)imidazole]), was synthesized by a convenient hydrothermal method. The structural analysis demonstrated that the compound was composed of metal–organic complexes containing pyim ligands, Keggin-type heteropolyacids, and transition metal copper ions. Remarkably, this not only solves the difficulty that the heteropolymeric acid cannot be recovered by dissolving in the solvent but also introduces the copper atom as a second active center. The catalyst exhibited a benzene conversion of 15.6% and a selectivity of 85.2% in a mixed solution of acetonitrile and acetic acid under optimal reaction conditions. After four catalytic cycles, the PXRD pattern proved that the catalyst was still stable. This study provides a good idea for photocatalytic reactions and other environmental applications. [ABSTRACT FROM AUTHOR]

The development of electrochemical nitrogen reduction reaction (NRR) catalysts with high catalytic activity and high stability is a significant challenge. In this work, a LaCu0.1Fe0.9O3−δ (LCuF) electrocatalyst for NRR was developed based on B-site Cu doping in the LaFeO3 (LF) perovskite. Good NRR catalytic performance and long-term stability were achieved when this catalyst was used as the cathode material for a protonic ceramic electrolysis cell (PCEC). Experimental results demonstrate that the synergistic effect between Cu and Fe enhances the NRR activity of this electrocatalyst. Electrons are transferred through the Fe–O2−δ–Cu chain, resulting in the formation of more Fe4+ at Fe sites and more Cu+ at Cu sites. This accelerates the electron transfer rate and thus increases the NRR rate. At the same time, more oxygen vacancies (OVs) are generated around Cu+. Fe4+ and OVs are both electron-deficient species, which are helpful for activating N2 by trapping metastable electrons in the anti-bonding orbitals of adsorbed nitrogen molecules. This work provides a viable strategy for developing a highly efficient NRR electrocatalyst. [ABSTRACT FROM AUTHOR]

Efficient bifunctional catalysts for oxygen evolution and reduction reactions (OERs/ORRs) are of great importance for sustainable and renewable clean energy, especially for metal–air batteries. Herein, we investigated β12-borophene with double-hole sites capped with 3d transition metal atoms to explore its catalyst performance for hydrogen evolution reactions (HERs), OERs and ORRs. It was found that the borophene is a good platform for diatomic site catalysts (DASCs) due to their advantage of stability over the corresponding single-atom catalysts (SACs) or clusters. The HER performance of DASCs on β12-BM was further improved compared to the SAC case. Furthermore, the supported FeNi DASC exhibited good catalytic performance for both OERs and ORRs, the overpotentials for which were 0.43 and 0.55 V, respectively, better than those of the corresponding supported Ni or Fe SAC due to synergistic effects. We herein propose a novel descriptor involving the Bader charges of coordinated atoms explicitly, behaving much better than the d-band center and integrated crystal orbital Hamilton population (-ICOHP) for DASCs. The synergistic effect of Fe–Ni pairs balanced the too strong binding of OH and further activated OH to achieve better catalytic performance. The results of this study can provide theoretical guidance for the design of efficient bifunctional electrocatalysts. [ABSTRACT FROM AUTHOR]

Pr0.5Sr0.5Cr0.1Fe0.9−xNixO3−δ (PSCFNx, x = 0.1, 0.2) catalysts are prepared and utilized as electrodes in symmetric solid oxide fuel cells (SOFCs) for the hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR). Although the PSCFNx cathode retains its perovskite phase during operation in SOFCs, the anode is totally decomposed and decorated with an exsolved metallic Ni–Fe alloy (denoted as re-PSCFNx) in a reducing atmosphere. Electrochemical impedance spectroscopy (EIS) combined with distribution of relaxation times (DRT) analysis reveals that the rate-limiting step for the HOR at the anode is the hydrogen adsorption–dissociation process, while the charge transfer process is found to dominate the ORR at the cathode. As the doping of Ni is increased, the cathode polarization resistance for the ORR decreases from 0.19 Ω cm2 for PSCFN0.1 to 0.09 Ω cm2 for PSCFN0.2 at 800 °C in air. A similar trend is observed for the anode polarization resistance for the HOR, which exhibits a reduction from 2.46 Ω cm2 of re-PSCFN0.1 to 1.28 Ω cm2 of re-PSCFN0.2 at 800 °C in H2. When fueled with hydrogen, a single cell based on the PSCFN0.2/La0.8Sr0.2Ga0.8Mg0.2O3−δ (LSGM)(240 μm)/re-PSCFN0.2 configuration delivers a maximum power density of 623 mW cm−2 and slight performance degradation when operated for 220 h at 800 °C. Ni doping results in the charge redistribution of B-site ions. Increasing the doping level of Ni results in additional electron transfer channels and oxygen vacancies that adsorb more oxygen species, which facilitates the ORR performance. Furthermore, an increase in the number of Ni–Fe nanoparticles and creation of abundant interfaces in the anode promote the HOR. This work suggests that PSCFN0.2 has the potential to be an excellent electrode material for a symmetric SOFC. [ABSTRACT FROM AUTHOR]

The anionic template method is an effective strategy for synthesizing high-nuclearity transition-lanthanide (3d–4f) heterometallic clusters. Herein, two lanthanide clusters with formulas [Gd20Ni21(μ3-OH)21(CO3)6(IDA)21(C2H4NO2)6(C2O4)3(MoO4)1.5(μ2-OH)1.5(H2O)9]Cl10.5·79H2O (1) and [Tb20Ni21(μ3-OH)21(CO3)6(IDA)21(C2H4NO2)6(C2O4)3(MoO4)(μ2-OH)2(H2O)10]Cl11·32H2O (2) were synthesized by introducing MoO42− anions as templates. Structural analysis indicates that compounds 1 and 2 are isomorphic, featuring a fascinating triangular-shaped metal framework. Magnetic property investigations illuminate the fact that compound 1 exhibits a large −ΔSm of 37.83 J kg−1 K−1 at 3 K for ΔH = 7 T. In particular, it is worth mentioning that compound 1 has an excellent low-field magnetic entropy (−ΔSm = 23.85 J kg−1 K−1 at 2 K, 2 T). [ABSTRACT FROM AUTHOR]

A Janus metastructure (MS) assisted by a waveguide structure (WGS) resting on anapole modes and exhibiting direction-dependent behavior has been developed in the terahertz (THz) region. Ultra-broadband absorption is formed by the destructive interference through the anapole as well as Janus trait and is shaped by nested WGS. In this design, vanadium dioxide (VO2) is expected to attain functional transformation from plasmon-induced transparency (PIT) to absorption. The insulating nature of the VO2 results in the creation of the PIT, which is characterized by a wide and high transmission window ranging from 1.944 THz to 2.284 THz, corresponding to the relative bandwidth of 7.4% above 0.9. However, when the VO2 reaches the metallic state, a high absorptivity of 0.921 at 2.154 THz can be implemented in the −z-direction owing to the excitement of the toroidal dipole and electric dipole moments in the near-infrared region. And in the +z-direction, the broadband absorption above 0.9 in the 1.448–2.497 THz range takes shape in virtue of surface plasmon polariton modes, in which intensely localized oscillation of free electrons is confined to the metal–dielectric interface supported by the WGS. Noting that the MS is equipped with a favorable sensitivity to the incidence angle, we develop an ultra-broadband backward absorption in the TM mode from 0.7–10 THz nearly all above 0.9 when the incidence angle changes from 30°–70°. Moreover, owing to the highly symmetrical structure, the MS exhibits exotic polarization angular stability. All the awesome properties make this MS a good candidate for various applications such as in electromagnetic wave steering, spectral analysis, and sensors. [ABSTRACT FROM AUTHOR]

The electronic structure and magnetic properties of the ferromagnetic Fe3GeTe2 monolayer have been extensively studied in recent years. Experimentally, external strain can be produced inevitably during the growth on the substrate. However, the impact of strain on the structural, electronic, and magnetic properties remains largely underexplored. Herein, by using density functional theory, we systematically investigate the crystalline configuration and electronic structure of the Fe3GeTe2 monolayer in the presence of external strain. We find that a moderate compressive strain could break the structural vertical symmetry, leading to a sizable out-of-plane dipole moment, while the ferromagnetism can be retained. Surprisingly, strain-induced polarization in the off-center Fe and Ge atoms barely contributes to the energy states at the Fermi level. The efficient decoupling of the conductivity and polarization in the strained Fe3GeTe2 monolayer results in an extremely rare phase with the coexistence of polarization, metallicity, and ferromagnetism, i.e., magnetic polar metals for potential applications in magnetoelectricity and spintronics. [ABSTRACT FROM AUTHOR]

Two polyoxometalate (POM)-based hybrid compounds have been successfully designed and constructed by the hydrothermal method with molecular formulas [K(H2O)2Fe II0.33 Co0.67(H2O)2(DAPSC)]2{[Fe II0.33 Co0.67(H2O)(DAPSC)]2[Fe II0.33 Co0.67(H2O)4]2[Na2Fe III4 P4W32O120]}·21.5H2O (1), and [Na(H2O)2Fe II0.33 Mn0.67(H2O)2(DAPSC)]2{[Fe II0.33 Mn0.67(H2O)(DAPSC)]2[Fe II0.33 Mn0.67(H2O)4]2[Na2Fe III4 P4W32O120(H2O)2]}·24H2O (2) (DAPSC = 2,6-diacetylpyridine bis-(semicarbazone)), respectively. Structural analysis revealed that 1 and 2 consisted of metal–organic complexes containing DAPSC ligands with dumbbell-type inorganic clusters, iron–cobalt (iron–manganese) and some other ions. By utilizing a combination of strongly reducing {P2W12} units and bimetal-doped centres the CO2 photoreduction catalytic capacity of 1 and 2 was improved. Notably, the photocatalytic performance of 1 was much better than that of 2. In CO2 photoreduction, 1 exhibited CO selectivity as high as 90.8%. Furthermore, for 1, the CO generation rate reached 6885.1 μmol g−1 h−1 at 8 h with 3 mg, and its better photocatalytic performance was presumably due to the introduction of cobalt and iron elements to give 1 a more appropriate energy band structure. Further recycling experiments indicated that 1 was a highly efficient CO2 photoreduction catalyst, which could still possess catalytic activity after several cycles. [ABSTRACT FROM AUTHOR]

The rising energy crisis and environmental problems are urging the development of more sustainable organic synthetic methods. Photoelectrocatalytic organic synthesis (PECOS) is emerging as an attractive strategy because it utilizes solar power to drive the organic synthesis and can greatly reduce the dependency on fossil fuels. Recently, a variety of organic reactions have been successfully realized using this strategy by rationally designing the photoelectrode and carefully tuning the reaction conditions. In this review, we introduce and categorize the recent advances in PECOS based on their specific reaction types, ranging from photoanode-mediated alcohol oxidation, C–H functionalization, furan oxidation, and sulfide oxidation, to (photo) cathode-mediated in situ H2O2 generation, cofactor regeneration, and the functionalization of aryl halides. The material of the photoelectrode, the reaction conditions of PECOS, and the proposed mechanism will be highlighted during the introduction of each example. Finally, we conclude by providing some perspectives on the future direction of PECOS. [ABSTRACT FROM AUTHOR]

Simultaneously achieving photoelectrochemical (PEC) water oxidation and degradation of organic pollutants coupled with H2 generation for bismuth vanadate (BiVO4) is highly desirable, while it is still hampered by low charge transport ability along with poor chemical durability. Herein, we have developed a NiFeOx co-catalyst decorated N-incorporated BiVO4 photoanode (N-BiVO4/NiFeOx), which not only can facilitate the charge transport efficiency but also efficiently suppresses the photo-corrosion. More specifically, the Fe sites trap photo-generated holes for promoting PEC processes and the Ni sites provide electrons to V sites for inhibiting V5+ dissolution of BiVO4. As a result, the large size N-BiVO4/NiFeOx photoanode with outstanding chemical stability exhibits efficient water oxidation and tetracycline hydrochloride (TCH) degradation coupled with H2 production performance. This work offers a promising avenue to design a high-performance photoanode and a new insight into antibiotic wastewater treatment. [ABSTRACT FROM AUTHOR]

Doubly-substituted methane isotopologues (13CH3D and 12CH2D2) can provide unique information to resolve the origin, transport, and conversion of environmental methane. We used a high-resolution mass spectrometer (Thermo Fisher Scientific 253 Ultra) to precisely determine Δ13CH3D and Δ12CH2D2 (precision and accuracy of ∼0.35‰ and ∼1.35‰ (1σ), respectively) in this study. The impacts of temperature, humidity, and slit quality are found to be critical for the reproducibility of the results, while the fragmentation rate and bellows effects on the clumped isotope results were negligible. A heating equilibrium experiment performed at 500 °C, 400 °C and 300 °C (n = 19) calibrates the results to an absolute reference. A pretreatment system that can extract methane having concentrations from ∼15% to ∼99.8% is proposed, while the fractionation produced throughout the pretreatment is negligible within precision (Δ13CH3D = +0.16 ± 0.32‰ and Δ12CH2D2 = +0.14 ± 1.12‰ (n = 16)). Analyses of natural gases from shale basins and variable methane-rich gases emitted from artificial lakes validate the capability of the current pretreatment and spectrometer systems to determine methane clumped isotopes in a wide range of natural environmental samples. [ABSTRACT FROM AUTHOR]

Ammonia is a promising carbon-free energy carrier. Ammonia is usually industrially synthesized via the Haber–Bosch method under high pressures and temperatures, which requires high energy consumption. In comparison, the electrocatalytic reduction of N2 is a green, eco-friendly, and pollution-free method for ammonia synthesis if the electricity is generated using a renewable source. Therefore, the development of highly efficient electrocatalysts for the N2 reduction reaction (NRR) would be significant. Herein, perovskites SrxTi0.6Fe0.4O3−δ (SxTF, x = 1 and 0.9) with tunable oxygen vacancies (OVs) were prepared and used as NRR electrodes for proton-conducting solid oxide electrolysis cells (PCECs). These PCECs were used to synthesize NH3 from N2 and H2. STF and S0.9TF showed maximum ammonia synthesis rates of 6.84 × 10−9 (±0.25 × 10−9) mol cm−2 s−1 and 4.09 × 10−9 (±0.80 × 10−9) mol cm−2 s−1, with corresponding Faraday efficiencies of 2.79% (±0.12%) and 2.01% (±0.09%) at 650 °C and 0.6 V. The enhanced NRR performance of S0.9TF was mainly attributed to the improved adsorption and activation of N2 by the abundant OVs, Ti3+ and the exsolved Fe active particles. This work offers a promising strategy for the design of materials for the electrochemical synthesis of NH3via PCECs. [ABSTRACT FROM AUTHOR]

Extensive global minimum searches augmented with first-principles theory calculations performed in this work indicate that the experimentally observed perfect inverse sandwich lanthanide boride complexes D7h La2B7− (1), D8h La2B8 (3), D9h La2B9− (7) can be extended to their actinide counterparts C2v Ac2B7− (1′), D8h Ac2B8 (3′), D9h Ac2B9− (7′) with a Bn monocyclic ring (n = 7–9) sandwiched by two Ac dopants. Such M2Bn−/0 inverse sandwiches (1/1′, 3/3′, 7/7′) can be used as building blocks to generate the ground-state C2 La4B13− (2)/Ac4B13− (2′), D2 La4B15− (4)/Ac4B15− (4′), C3v/C3 La4B18 (5)/Ac4B18 (5′), Oh Ac7B24+ (6′), Oh Ac7B24, Td Ac4B24 (8′), C1 La5B24+ (9)/Ac5B24+ (9′), and Td Ac4B29− (10′) which are based on boron frameworks consisting of multiple conjoined Bn rings (n = 7–9). Detailed bonding analyses show that effective (d–p)σ, (d–p)π and (d–p)δ coordination bonds are formed between the Bn rings and metal doping centers, conferring three-dimensional aromaticity and extra stability to the systems. In particular, the perfect body-centered cubic Oh Ac7B24+ (6′) and Oh Ac7B24 with six conjoined B8 rings can be extended in x, y, and z dimensions to form one-dimensional Ac10B32 (11′), two-dimensional Ac3B10 (12′), and three-dimensional AcB6 (13′) nanomaterials, presenting a B8-based bottom-up approach from metal boride nanoclusters to their low-dimensional nanomaterials. [ABSTRACT FROM AUTHOR]

The pathological mineralization of calcium oxalate monohydrate (COM) crystals in vivo inevitably brings renal injury wherein natural macromolecules play an indispensable role in regulating the process. However, the role of macromolecules in crystal growth is more complicated and less well understood. In this study, we innovatively propose two proteins extracted from earthworms, lumbrokinase (LRK) and earthworm protein (EP), as potent modifiers of calcium oxalate (CaOx) crystals. Our research shows that LRK and EP inhibit COM formation and initiate the calcium oxalate dihydrate (COD) phase, which is more easily excreted out of the body. Through a series of combined macroscopic and microscopic experimental techniques, we reveal the site-specific adsorption of inhibitors on the COM (121¯) and (021) surface, resulting in a reduction in the aspect ratio. In situ atomic force microscopy (AFM) measurements show that LRK and EP specifically inhibit the advancement of COM surface steps through more than one inhibition mode. In general, the discovery of natural macromolecules from earthworms as potent inhibitors of COM crystal formation provides some insights into the appropriate formulation of inhibitors, which could prevent the formation of undesired stones in the kidney. Our findings shed light on nature's remarkable mineralization capabilities and outline fabrication strategies for advanced materials. [ABSTRACT FROM AUTHOR]

Several borophenes have been prepared successfully, but the synthesis of boron nanotubes is still very difficult. Our results suggest that the high flexibility of borophene in combination with van der Waals interactions makes it possible to coil boron nanotubes from rippled borophenes, which is confirmed by ab initio molecular dynamics simulations. The plane structures transform into rippled structures almost without any barrier under very small compression and weak perturbations like molecular adsorption. The compression energies of the rippled structures increase linearly and slowly with the increase of the compression. This suggests how the geometry of the borophene evolves with compression. Based on the evaluation of the free energy of hydrogen adsorption, a stronger compression suggests the improved hydrogen evolution performance of the borophene and even makes it better than Pt catalysts. Meanwhile, good hydrogen evolution performance is also suggested for boron nanotubes. Our results suggest a novel preparation method for boron nanotubes from borophenes and a possible way to improve their hydrogen evolution performance. [ABSTRACT FROM AUTHOR]

The electrocatalytic ethanol oxidation reaction (EOR) is a critical component of direct ethanol fuel cells, while its reactivity, stability, and selectivity toward C1 products are severely hindered by the poisoning effect of CO species on the surface of noble-metal catalysts. In this work, we developed a hybrid material of palladium nanoparticles and nickel single-atom catalysts (Pd NPs@Ni SAC) for efficient EOR. The Pd nanoparticles catalyze the breaking of carbon–carbon bonds of ethanol, while the adsorbed CO intermediates are removed by the Ni single-atom catalyst. The Pd NPs@Ni SAC structure exhibits outstanding EOR performances, including high mass activity, good selectivities of C1 products, and excellent electrocatalytic stability. Our work suggests an attractive perspective of utilizing single-atom electrocatalysts for ethanol oxidation. [ABSTRACT FROM AUTHOR]

It is well-known that transition-metal-doping induces dramatic changes in the structures and bonding of small boron clusters, as demonstrated by the newly observed perfect inverse sandwich D8h [La(η8-B8)La] and D9h [La(η9-B9)La]−. Based on extensive global minimum searches and first-principles theory calculations, we predict herein the possibility of perfect endohedral trihedral metallo-borospherene D3h La@[La5&B30] (1, 3A′1) and its monoanion Cs La@[La5&B30]− (2, 2A′) and dianion D3h La@[La5&B30]2− (3, 1A′1). These La-doped boron clusters are composed of three inverse sandwich La(η8-B8)La on the waist and two inverse sandwich La(η9-B9)La on the top and bottom which share one apex La atom at the center and six periphery B2 units between neighboring η8-B8 and η9-B9 rings, with three octo-coordinate La atoms and two nona-coordinate La atoms as integrated parts of the cage surface. Detailed adaptive natural density partitioning (AdNDP) and iso-chemical shielding surface (ICSS) analyses indicate that La@[La5&B30]0/−/2− (1/2/3) are spherically aromatic in nature. The one-dimensional nanowire La4B21 (4, P31m) constructed from D3h La@[La5&B30] (1) along the C3 axis of the system appears to be metallic. The IR and Raman spectra of La@[La5&B30] (1) and photoelectron spectroscopy of the slightly distorted Cs La@[La5&B30]− (2) are theoretically simulated to facilitate their spectroscopic characterizations. [ABSTRACT FROM AUTHOR]

In this work, organic supramolecular linkers involving cucubit[6]urils CB[6] and N,N′-hexamethylene-bis(pyrazinyl hexafluorophosphate) (BPHF@CB[6]) were utilized to assemble dodenuclear silver chalcogenolate clusters into three one-dimensional (1D) materials under different synthesis conditions. These three crystal structures of CB[6]-based sliver cluster-organic rotaxane frameworks were well resolved, and their emission properties were investigated systematically. This construction strategy involving organic supramolecular linkers gives a new methodology for cluster-assembled materials with intriguing structural and functional properties. [ABSTRACT FROM AUTHOR]

The electrocatalytic reduction of carbon monoxide (CO) is an emerging direction with new catalyst structures, among which the bimetallic component catalysts feature both functional diversity and high-density of active sites. In this work, we demonstrate that the fine tuning of adjacent bimetallic sites can allow us to select different reaction pathways toward C1 or C2 products in the electroreduction of CO. Cu and Cu–Au alloy catalysts with different atomic ratios were fabricated and investigated for appropriate molecular distances. The pure Cu catalyst was found to be active for electroreducing CO to C2H4, as the adjacent Cu sites were beneficial for adsorbing multiple CO molecules and subsequent C–C coupling. On the other hand, alloying Cu with Au introduced steric hindrance and a larger intermolecular distance between adjacent adsorbed *CO intermediates, thus leading to a decrease of C2H4 selectivity but an enhanced CH4 pathway. Our work revealed the importance of spacing between active sites for CO electroreduction, which can benefit the catalyst design to further improve activities and selectivities in electrocatalytic CO reduction. [ABSTRACT FROM AUTHOR]

La-[B2@B18]-La demonstrates decisive changes of the properties of molecular rotors, from multiple (here 18) equivalent individual global minimum structures to a quantum mechanical unified structure. This affects their geometries, their symmetries (18*C2h → D9d), the generation of energy bands, and high-resolution spectroscopy. [ABSTRACT FROM AUTHOR]

The highly enantioselective copper-catalyzed propargylic amination of propargylic esters with amine hydrochloride salts has been realized for the first time using copper salts with chiral N,N,P-ligands. This method features a broad substrate scope and wide functional group tolerance, generating propargylic amines in good to excellent yields with high enantioselectivities (up to 99% ee). The utility of the approach was demonstrated by late-stage functionalization of marketed pharmaceuticals. [ABSTRACT FROM AUTHOR]

We proposed a method to regulate nucleic acid polymerization by proximity and designed an ultrasensitive biosensor based on proximity-induced exponential amplification reaction for proximity assay of proteins (streptavidin) and small molecules (adenosine triphosphate), which allows us to detect a variety of interesting targets by simply changing the binding sites of DNA. [ABSTRACT FROM AUTHOR]

A novel high-nuclearity silver sulfide nanocluster [Ag50S7(SC6H4F)36(dppp)6]·4DMI, (hereafter abbreviated as 1⋅4DMI) was synthesised. Solvent-free crystals of 1 displayed a completely reversible narrowing and broadening of the optical band gap that was accompanied by visual thermochromism and piezochromism changeovers, when stimulated by varying temperatures between 113 and 413 K or by changing the pressure from 1 atm to 7.5 GPa. [ABSTRACT FROM AUTHOR]

Exploring economic, scalable, and highly efficient carbon materials for the oxygen reduction reaction (ORR) is of great significance to a variety of renewable energy conversion and storage technologies. Herein, we directly convert soya peptone as a carbon precursor to a series of mesoporous nanocarbon-based materials for the ORR via a one-step pyrolysis process combined with the help of ZnCl2 as an activator. Benefiting from the effective chemical activation effect during carbonization, the optimal electrocatalysts possess mesoporous structures and high surface area (>1000 m2 g−1) which favor fast mass transport, electron transfer, and exposure of abundant active sites. Remarkably, the electrocatalysts show a comparable ORR catalytic performance, excellent stability, and superior methanol tolerance, comparable to the commercial Pt/C catalyst. Thus, soya peptone biomass derived carbon materials are surely helpful for providing a new space to develop ORR electrocatalysts. [ABSTRACT FROM AUTHOR]

Vanadium cluster anions are highly reactive making the preparation of pure Vn− and the observation of their reactivity extremely challenging. Herein, well-resolved anionic Vn− clusters are prepared enabling an in-depth study on their reactions with O2 in the gas phase. While pure metal clusters of a magic number are not identified due to the strong V–O bonding, interestingly an unexpected oxide V11O15− was experimentally observed in surviving O2 etching reactions. First-principles theory calculations indicate that V11O15− possesses a body-centered pentagonal prism structure (D5h,), with the V@V10 core fully protected by 15 oxygen bridges. Such an oxygen-protected metal cluster [V@V10O15]− exhibits typical superatom orbital features pertaining to the V@V10 core which shows effective metal–metal coordination bonding. Meanwhile, the high stability of [V@V10O15]− is reinforced by the V–O–V conjugation interactions which help to maintain the structural integrity, resulting in 3D inorganic aromaticity. This finding of such an oxygen-passivated superatom cluster sheds light on the bonding nature in ligand-protected metal clusters via wet synthesis. [ABSTRACT FROM AUTHOR]