Search

A pure inorganic uranyl phosphate-polyoxometalate of Na17{Na@[(SbW9O33)2(UO2)6(PO3OH)6]}·xH2O (abbreviated as Na@U6P6, with x ≈ 46) featuring a sandwich-type structure was prepared using Keggin-type trilacunary [α-B-SbW9O33]9- units as building blocks, which were formed in situ by SbCl3 and Na2WO4·2H2O. Crystal structural analysis showed that six UO22+ cations and six PO3OH2- anions generated a wheel-like cluster unit with a Na+ center ([Na@(UO2)6(PO3OH)6]+) that is stabilized by two [α-B-SbW9O33]9- units. Na@U6P6 displayed a solid-state photoluminescence quantum yield of 33% at 300 K. The temperature-dependent fluorescence emission spectra showed that Na@U6P6 has temperature-sensitive fluorescence in which its emission intensity decreased by 77% as the temperature increased from 200 to 300 K. These results suggest that such uranyl phosphate-polyoxometalate clusters could serve as potential temperature-sensitive molecular materials.

Great importance has been attached to magnetoelectric coupling in multiferroic thin films owing to their extremely practical use in a new generation of devices. Here, a film of [(n-C3H7)4N][FeIIIFeII(dto)3] (1; dto = C2O2S2) was fabricated using a simple stamping process. As was revealed by our experimental results, in-plane ferroelectricity over a wide temperature range from 50 to 300 K was induced by electron hopping between FeII and FeIII sites. This mechanism was further confirmed by the ferroelectric observation of the compound [(n-C3H7)4N][FeIIIZnII(dto)3] (2; dto = C2O2S2), in which FeII ions were replaced by nonmagnetic metal ZnII ions, resulting in no obvious ferroelectric polarization. However, both ferroelectricity and magnetism are related to the magnetic Fe ions, implying a strong magnetoelectric coupling in 1. Through piezoresponse force microscopy (PFM), the observation of magnetoelectric coupling was achieved by manipulating ferroelectric domains under an in-plane magnetic field. The present work not only provides new insight into the design of molecular-based electronic ferroelectric/magnetoelectric materials but also paves the way for practical applications in a new generation of electronic devices.

Cocrystallization of different metal nanoclusters facilitates the preparation of cluster-based nanomaterials with enhanced properties. Herein, two pairs of enantiomeric 3d-4f cocrystallization structures of clusters R/S-[Mn10Ln6] and R/S-[Mn6Ln2] (Ln = Dy for 1R and 1S, Y for 2R and 2S) have been reported. Compounds R/S-[Mn10Ln6][Mn6Ln2] exhibit a large optical activity and magneto-optic effect as verified by natural circular dichroism (NCD) and magnetic circular dichroism (MCD). In addition, alternating current (ac) magnetic measurements show that the chiral R/S-[Mn10Dy6][Mn6Dy2] cocrystallization structure displays slow magnetic relaxation with Ueff = 25.1 K.

Recently, Pt-based intermetallic nanoparticles (iNPs) have been intensely studied to improve the electrocatalytic activity/stability and Pt atomic utilization, but how to control the size of Pt-bas...

The magnetodielectric effect is closely related to multiferroic or magnetoelectric coupling; thus, it can be used to predict magnetoelectric coupling, especially in compounds with special magnetic properties. The magnetodielectric response can often be used to predict many interesting and meaningful physical coupling mechanisms. Therefore, fabricating magnetodielectric materials is an effective step toward the development of magnetoelectric materials. Herein, we synthesize the mixed-valence layered ferrimagnetic molecular compound (C

Reported herein are the synthesis and structures of two high-nuclearity AuAg nanoclusters, namely, [Au78Ag66(C≡CPh)48Cl8]q− and [Au74Ag60(C≡CPh)40Br12]2–. Both clusters possess a three-concentric-s...

Here we report for the first time soluble lanthanide-transition-metal clusters Ln36Co12 (Ln = Eu, Gd and Dy) as effective homogeneous water oxidation electrocatalysts. The stable 48-metal Ln36Co12 clusters show an effective water oxidation activity under acidic conditions because of the synergistic effect between lanthanide and transition metals in O-O bond formation.

Polar organic-inorganic hybrid materials have been applied in ferroelectricity, as well as in devices based on nonlinear optical and piezoelectricity properties. Here, we used a rectangular pyramid structure of [VOCl4]2- to construct a polar compound (C5NH13Cl)2VOCl4 (1). Compound 1 crystallized in the monoclinic P21 space group. Coexistence of nonlinear optical switching behavior (space-group change from P21 to P21/n) and two-staged thermosensitive dielectric switching properties could be achieved under the stimulus of temperature. Our findings provide an effective approach for construction of polar materials.

Incorporating metal clusters within the skeleton of the organic polymers through click reaction can not only effectively prepare cluster-polymer composites, but also effectively avoid the cluster aggregation. Herein, an azide-contatining Lanthanide-Titanium oxo cluster of Eu 8 Ti 10 -N 3 ( Eu 8 Ti 10 -N 3 = [Eu 8 Ti 10 ( µ 3 -O) 14 (H 2 O) 4 (OAc) 2 (tbba) 30 (paza) 4 (THF) 2 ]•4THF•8H 2 O ( 1 ), Htbba = 4-tert-butylbenzoic acid, Hpaza = 4-azidobenzoate, HOAc = acetic acid, THF = Tetrahydrofuran) through in situ solvothermal reaction of 4-Azidobenzoic acid and 4-tert-butylbenzoic acid. Reaction of 1 with PEG ( PEG = Methoxypoly(ethyleneglycol)alkyne, 2000 g/mol) through Cu(I)-catalyzed click chemistry generates a lanthanide-polymer composite of Eu 8 Ti 10 -N 3 @PEG ( 2 ). Investigation on IR, 1 H NMR ICP-OES of 2 indicates that the structural integrity of 1 is maintained in 2 . Study on luminescent properties of 1 and 2 reveals that the quantum yield of 1 itself basically keeps unchanged in 2 . Significantly, the formation of 2 can not only effectively prevent the cluster 1 from aggregation, but also greatly enhance its solubility and adhesion to the substrate. Owing to the solubility and adhesion of luminescent materials being the key to their practical application, present work is thus of great significance for the development of metal cluster-polymer composite luminescent materials.

Generally, compared to conjugated chain molecules, aromaticity provides additional stability for the cyclic, planar, and conjugated molecules. Thus, the concept of aromaticity was undeniably utilized to explain the unique stability for extensive cyclic molecules (notably for benzene, recently reported boron rings, and all-metal multiply aromatic Al42- salts) to guide chemical syntheses. However, can aromaticity alone describe the stability for all of those cyclic and planar clusters or molecules? In this regard, we observed the four-membered prototypical rings: c-M2O2-/0 clusters (M = B, Al, Ga, and In) possessing unique rhombic (four-center, four-electron) π and σ o-bonds, which are considered to have 3-fold aromaticity. Moreover, we not only elucidated the key role of ring strain energy (RSE) to determine the stability of these rings but also unexpectedly revealed that the electrostatic interaction (ionicity) plays a fundamental role in the stability of Al2O2-/0 clusters through systematically experimental and theoretical investigations into the isolated M2O2-/0 clusters (M = B, Al, Ga, and In). Detailed geometries, molecular orbital, and chemical bonding nature were analyzed to unravel those influences. This work provides a clue in which RSE and the electrostatic effect should be carefully taken into account for the stability of diverse cyclic clusters or molecules compared to the expected stability factor from aromaticity.

Metal clusters with well-defined crystal structures are extremely useful for studying the synergistic catalytic effects and associated catalytic mechanisms. In this study, two pairs of chiral lanthanide-transition metal clusters

In situ cross-linking encapsulation has been demonstrated to be an efficient strategy for enhancing the humidity stability of perovskite solar cells (PSCs). In this study, a novel cross-linkable fullerene derivative, namely 1-(p-benzoate-(p-methylvinylbenzene)-indolino[2,3][60] fullerene (FPPS), was readily synthesized from commercially available building blocks in two steps. This FPPS was employed as an interfacial modifier on perovskite surfaces in inverted planar p–i–n PSCs. Owing to the fast interfacial charge extraction and efficient trap passivation, PSCs based on the cross-linked FPPS (C-FPPS) exhibited excellent performance. The PSCs had a top-performing power conversion efficiency (PCE) of 17.82% with negligible hysteresis, compared to the control devices without C-PFFS (16.99%). Moreover, the strong water resistance of the C-FPPS interfacial layer distinctly enhances the ambient stability of PSC devices, exhibiting a t80 (the time required to reach 80% of the initial PCE) of 300 h under high-humidity conditions. This significantly surpasses the control devices, whose t80 was only 130 h. These results demonstrate that cross-linkable fullerene derivatives can be promising interfacial materials for designing high-efficiency, hysteresis-free, air-stable PSCs.

Summary Nanoscale molecular materials obtained from building-block methods have flourished in recent years and have stimulated further efforts to more challenging systems. Employing building blocks to assemble atomically precise giant clusters is one of the most striking fields but is quite challenging. Here, we report the synthesis of two giant lanthanide-transition metal clusters, Ln68Ni90 and Ln76Ni88, by combining the identification of building blocks through data analysis, the determination of their formation conditions by high-resolution mass spectrometry, and the design of new structures based on topological analysis. Compared with established one-pot methods, synthesizing the building blocks separately provides extra evolution chances for the building blocks and facilitates efficient synthesis. In particular, this study focused on challenging giant heterometallic systems, and the clusters set a new nuclearity record. These results demonstrate the design-driven synthesis of hydroxide clusters from their building blocks and might advance the directed synthesis of giant clusters.

The formation mechanism of ferrihydrite is the key to understand its treatment of pollutants in waste water and purification of surface water and groundwater. Although emerging evidence suggests that formation of the ferrihydrite occurs through the aggregation of prenucleation clusters, rather than classical atom-by-atom growth, its formation mechanism remains unclear. Herein, an iron-oxo anionic cluster of [Fe22 (μ4 -O)8 (μ3 -OH)20 (μ2 -OH)18 (CH3 COO)16 (H2 O)2 ]4- viewed as a dimer of bivacant β-Keggin-Fe13 clusters was for the first time obtained by using lanthanide ions as stabilizers. Upon dissolution in a mixed solution of isopropanol and water, the lacunary β-Keggin-Fe13 cluster can transform into an α-Keggin-Fe13 cluster, distinctly demonstrating that the Keggin-Fe13 cluster rotational isomerization can be realized through the vacant Keggin-Fe13 cluster.

Two high-nuclearity lanthanide-transition metal clusters with the general formula [Ln18CoIICoIII6(OH)14(CO3)9(CH3CH2COO)6(dea)12(H2O)30]·(NO3)8·Cl4·(CH3CH2OH)6·(H2O)12 (Ln18Co7, Ln = Gd (1) and Dy ...

All-inorganic and earth-abundant bi-/trimetallic hydr(oxy)oxides are widely used as oxygen evolution electrocatalysts owing to their remarkable performance. However, their atomically precise struct ...

The structure-dependent thermal stability of fullerene electron transport layers (ETLs) and its impact on device stability have been underrated for years. Based on cocrystallographic understanding, herein, we develop a thermally stable ETL comprising a hybrid layer of [6,6]-phenyl-C

Polar crystal structures have attracted more and more attention, due to their unique characteristics, such as ferroelectricity, piezoelectricity, and nonlinear optical property, etc. However, the construction of polar materials is always accidental, and finding an effective synthesis strategy to construct polar materials remains a challenge. Herein, inorganic-organic hybrid compounds of [C7H14N][FeCl4] (1) ([C7H14N] = quinuclidinium cation) and [C7H14N][GeCl3] (2) were prepared, respectively, to verify the beneficial effect of polar anions on the construction of polar crystals. Compound 1 crystallized in the Pbca space group, while 2 belongs to the P43 space group at room temperature. Investigation into the structure of 2 reveals that the polarity of 2 derives from the triangular pyramid structure of [GeX3]- with lone pair electrons. Meanwhile, 2 undergoes a phase transition from the P43 space group to the center Pm3m at 385 K, leading to the optic-electric switching property. Thus, the present work exhibits the advantage of [GeX3]- as the inorganic constituent component in the hybrid polar materials and provides an effective approach for the construction of a polar molecule-based crystal with a switchable property.

In the absence of inorganic anion templates and in high pH condition (pH ∼ 14), an unprecedented carbonate-hydrate supramolecule, [(CO3)2(H2O)]4−, trapped from atmospheric CO2, found to play an ani...

Atomically precise molecular metal-oxo clusters provide ideal models to understand metal oxide surfaces, self-assembly, and form-function relationships. Devising strategies for synthesis and isolation of these molecular forms remains a challenge. Here, the synthesis of four Ln-Fe oxo clusters that feature the ϵ-{Fe13 } Keggin cluster in their core is reported. The {Fe13 } metal-oxo cluster motif is the building block of two important iron oxyhydroxyide phases in nature and technology, ferrihydrite (as the δ-isomer) and magnetite (the ϵ-isomer). The reported ϵ-{Fe13 } Keggin isomer as an isolated molecule provides the opportunity to study the formation of ferrihydrite and magnetite from this building unit. The four currently reported isostructural lanthanide-iron-oxo clusters are fully formulated [Y12 Fe33 (TEOA)12 (Hyp)6 (μ3 -OH)20 (μ4 -O)28 (H2 O)12 ](ClO4 )23 ⋅50 H2 O (1, Y12 Fe33 ), [Gd12 Fe33 (TEOA)12 (Hyp)6 (μ3 -OH)20 (μ4 -O)32 (H2 O)12 ](ClO4 )15 ⋅50 H2 O (2, Gd12 Fe33 ) and [Ln16 Fe29 (TEOA)12 (Hyp)6 (μ3 -OH)24 (μ4 -O)28 (H2 O)16 ](ClO4 )16 (NO3 )3 ⋅n H2 O (Ln=Y for 3, Y16 Fe29 , n=37 and Ln=Gd for 4, Gd16 Fe29 n=25; Hyp=trans-4-Hydroxyl-l-proline and TEOA=triethanolamine). The next metal layer surrounding the ϵ-{Fe13 } core within these clusters exhibits a similar arrangement as the magnetite lattice, and Fe and Ln can occupy the same positions. This provides the opportunity to construct a family of compounds and optimize magnetic exchange in these molecules through composition tuning. Small-angle X-ray scattering (SAXS) and high-resolution electrospray ionization mass spectrometry (HRESI-MS) show that these clusters are stable upon dissolution in both water and organic solvents, as a first step to performing further chemistry towards building magnetic arrays or investigating ferrihydrite and magnetite assembly from pre-nucleation clusters.

In this study, a porous hybrid catalyst with carbon-confined Ni2P porous nanosheet arrays supported on nickel foam (Ni2P@C NAs/NF) was developed via a one-step phosphorization of NiMOF precursor. Remarkably, the as-fabricated Ni2P@C NAs/NF exhibited superior oxygen evolution reaction (OER) performance and only required a small overpotential of 243 mV to deliver a current density of 15 mA cm−2, which surpassed most reported noble-metal-free based OER catalysts working in alkaline media. Such striking results could be ascribed to the synergistic effect between the interconnected macroporous structure (facilitating mass transport and exposing rich accessible catalytic centers) and the modulated electronic states induced by electron transfer from the carbon matrix to nickel phosphide (optimizing its intrinsic electrocatalytic property). In particular, the alkaline two-electrode water electrolyser, which was assembled by simultaneously utilizing Ni2P@C NAs/NF as the cathode and anode, showed considerable water-splitting activity and durability. Additionally, systematic post-electrolysis structural study confirmed the in situ formation of a γ-NiOOH film on the Ni2P surface at the anode. This work provides a deep insight into the post-electrolysis structure of nickel-containing catalyst materials and would be helpful for the design of three-dimensional porous hybrid nanocatalysts.

A heterometallic 3d–4f compound formulated as {[CoIII2Dy3Na(CH3CH2COO)6(OH)6(NO3)4(H2O)2]·H2O}n (1) has been synthesized and structurally characterized. The Co2Dy3 metal core adopts trigonal bipyramidal (TBP) geometry. Compound 1 displays single-molecule magnet behavior with an energy barrier of 60.3 K under a zero dc field.

Preventing the stacking of two-dimensional (2D) structured nanomaterials is important for developing high-performance gas sensors. To address this challenge, three-dimensional (3D) hollowed-out hierarchical Fe2O3 microrods assembled by nanosheets were successfully fabricated via a facile MgO-mediated chemical template conversion strategy. Structurally, the large active surface area of the microrods significantly enhanced gas adsorption, thereby resulting in a high response. Additionally, the hollow interior and the well-aligned porous structure between adjacent nanosheets were favorable for the rapid diffusion of detected gases, reducing the response/recovery times. Gas sensing measurements revealed that the nanosheet-assembled, hollowed-out hierarchical γ-Fe2O3 microrods calcined at 300 °C (i.e., Fe2O3-300) exhibited the best performance among the as-prepared samples with different phases. Strikingly, the sensitivity to 100 ppm acetone at 220 °C reached 125.5, and the response/recovery times were only 0.9/15 s, respectively. Compared to α-Fe2O3 obtained at 500 °C (i.e., Fe2O3-500), Fe2O3-300 with the γ-phase exhibits superior capacity to chemisorb oxygen and the bulk resistance effect, which are intrinsically beneficial for enhancing its gas sensing performance. In addition, the as-synthesized nanosheet-assembled, hollowed-out hierarchical γ-Fe2O3 microrods exhibited outstanding repeatability and remarkable long-term stability, which suggests their potential application in fabricating highly sensitive gas sensors. This work provides a viable approach for synthesizing various nanosheet-assembled, hollowed-out hierarchical metal oxides.

Thiacalix[4]arenes as a family of promising ligands have been widely used to construct polynuclear metal clusters, but scarcely employed in silver nanoclusters. Herein, an anion-templated Ag88 nanocluster (SD/Ag88a) built from p-tert-butylthiacalix[4]arene (H4TC4A) is reported. Single-crystal X-ray diffraction reveals that C4-symmetric SD/Ag88a resembles a metal-organic super calix comprised of eight TC4A4− as walls and 88 silver atoms as base, which can be deconstructed to eight [CrO4@Ag11(TC4A)(EtS)4(OAc)] secondary building units arranged in an annulus encircling a CrO42− in the center. Local and global anion template effects from chromates are individually manifested in SD/Ag88a. The solution stability and hierarchical assembly mechanism of SD/Ag88a are studied by using electrospray mass spectrometry. The Ag88 nanocluster represents the highest nuclearity metal cluster capped by TC4A4−. This work not only exemplify the specific macrocyclic effects of TC4A4− in the construction of silver nanocluster but also realize the shape heredity of TC4A4− to overall silver super calix., The assembly of giant silver clusters by using macrocylic multidentate ligand remains a challenge. Here, the authors synthesize a chromate-templated 88-nuclei silver super calix and reveal the role of anion templating effects and a hierarchical assembly mechanism.

In the last two decades, metal-organic frameworks (MOFs), as a class of porous crystalline materials formed by organic linkers coordinated-metal ions, have attracted increasing attention due to their unique structures and wide applications. Compared to single components, various well-designed MOF-based composites combining MOFs with other functional materials, such as nanoparticles, quantum dots, natural enzymes and polymers with remarkably enhanced or novel properties have recently been reported. To efficiently and directionally synthesize high-performance MOF-based composites for specific applications, it is vital to understand the structural-functional relationships and role of MOFs. In this review, preparation methods of MOF-based composites are first summarized and then the relationship between the structure and performance is determined. The functions of MOFs in practical use are classified and discussed through various examples, which may help chemists to understand the structural-functional relationship in MOF-based composites from a new perspective.

Two pairs of enantiomeric 3d–4f metal clusters, [Co2Ln[(R)/(S)-L]4]·Cl5·(H2O)2·CH3OH·CH3CH2OH [Co2Ln; Ln = Gd (1S and 1R), Dy (2S and 2R)], were synthesized by the reaction of chiral Schiff-base li...

The combination of CrO42− anion and N , N ′-dimethylformamide (DMF)-containing solvent helps to stabilize an atom-precise ultrasmall Ag6 kernel into a 52-nuclei silver shell, giving a core-shell Ag6@Ag52 wheel-like structure ( SD/Ag58b ). The solution behavior and photocurrent response property were investigated in details.

Recently, metal-organic framework (MOF)-based multienzyme systems integrating different functional natural enzymes and/or nanomaterial-based artificial enzymes are attracting increasing attention due to their high catalytic efficiency and promising application in sensing. Simple and controllable integration of enzymes or nanozymes within MOFs is crucial for achieving efficient cascade catalysis and high stability. Here, we report a facile electrochemical assisted biomimetic mineralization strategy to prepare an artificial multienzyme system for efficient electrochemical detection of biomolecules. By using the GOx@Cu-MOF/copper foam (GOx@Cu-MOF/CF) architecture as a proof of concept, efficient enzyme immobilization and cascade catalysis were achieved by in situ encapsulation of glucose oxidase (GOx) within MOFs layer grown on three-dimensional (3D) porous conducting CF via a facile one-step electrochemical assisted biomimetic mineralization strategy. Due to the bio-electrocatalytic cascade reaction mechanism, this well-designed GOx@Cu-MOF modified electrode exhibited superior catalytic activity and thermal stability for glucose sensing. Notably, the activity of GOx@Cu-MOF/CF still remained at ca. 80% after being incubated at 80 °C. In sharp contrast, the activity of the unprotected electrode was reduced to the original 10% after the same treatment. The design strategy presented here may be useful in fabricating highly stable enzyme@MOF composites applied for efficient photothermal therapy and other platform under high temperature.

Building blocks with multiple components are promising for the synthesis of complex molecular assemblies, but are rarely available. Herein, we report a modification procedure for a multi-component building block [Ln

Accurately controlling the hydrolysis of metal ions can not only yield the desired structure of metal hydroxide clusters but also provide a deeper understanding of the formation process of natural hydroxide minerals. However, the capture of hydrolysis intermediates remains a significant challenge, and metal hydroxide clusters are mainly obtained by employing adventitious hydrolysis. In this study, we realized a hierarchical building block assembly from Y

A 3D borate–carbonate framework, GdB(OH)4CO3 (1), was synthesized. Magnetic study reveals that its MCE is up to 33.5 J kg−1 K−1 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.

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

A high-nuclearity 3d-4f cluster of [Gd

A 3D coordination polymer, [Gd(HCOO)(C

Hydrogen is regarded as an attractive alternative energy carrier due to its high gravimetric energy density and only water production upon combustion. However, due to its low volumetric energy density, there are still some challenges in practical hydrogen storage and transportation. In the past decade, using chemical bonds of liquid organic molecules as hydrogen carriers to generate hydrogen in situ provided a feasible method to potentially solve this problem. Research efforts on liquid organic hydrogen carriers (LOHCs) seek practical carrier systems and advanced catalytic materials that have the potential to reduce costs, increase reaction rate, and provide a more efficient catalytic hydrogen generation/storage process. In this work, we used methanol as a hydrogen carrier to release hydrogen in situ with the single-site Pt1/CeO2 catalyst. Moreover, in this reaction, compared with traditional nanoparticle catalysts, the single site catalyst displays excellent hydrogen generation efficiency, 40 times higher than 2.5 nm Pt/CeO2 sample, and 800 times higher compared to 7.0 nm Pt/CeO2 sample. This in-depth study highlights the benefits of single-site catalysts and paves the way for further rational design of highly efficient catalysts for sustainable energy storage applications.

A mixed-valent hexadecanuclear manganese cluster, [MnII2MnIII14(trz)14(thetach)4(μ3-O)8(H2O)10](ClO4)6 (Mn16), containing two MnII and 14 MnIII ions, is constructed from mixed in situ generated ligands, 1,2,3-triazole (Htrz) and 1,3,5-tri(2-hydroxyethyl)-1,3,5-triazacyclohexane (H3thetach). Remarkably, both ligands were not initially added into the reaction system, and their formations involve the in situ ligand decomposition and subsequent condensation reactions. The core of Mn16 is an elongated torus comprised of eight Mn atoms and four [Mn2O2] subunits bridged by oxo or alkoxide. The high-resolution electrospray ionization mass spectrometry (HR-ESI-MS) of Mn16 dissolved in CH3CN indicates its structure remains intact as +3 and +4 species. Temperature and field dependent magnetization revealed predominantly antiferromagnetic exchange interactions within the cluster. The work provides one-pot synthesis of high-nuclearity manganese clusters using the ligands generated by in situ reactions in a tandem fashion.

Control over core structure is much more challenging than that over shell structure in core–shell silver nanoclusters. Herein, two isostructural chalcogen-mediated [Ag6Z4@Ag36] (Z = S or Se) nanocl...

All previously reported C70 isomers have positive curvature and contain 12 pentagons in addition to hexagons. Herein, we report a new C70 species with two negatively curved heptagon moieties and 14 pentagons. This unconventional heptafullerene[70] containing two symmetric heptagons, referred to as dihept-C70 , grows in the carbon arc by a theoretically supported pathway in which the carbon cluster of a previously reported C66 species undergoes successive C2 insertion via a known heptafullerene[68] intermediate with low energy barriers. As identified by X-ray crystallography, the occurrence of heptagons facilitates a reduction in the angle of the π-orbital axis vector in the fused pentagons to stabilize dihept-C70 . Chlorination at the intersection of a heptagon and two adjacent pentagons can greatly enlarge the HOMO-LUMO gap, which makes dihept-C70 Cl6 isolable by chromatography. The synthesis of dihept-C70 Cl6 offers precious clues with respect to the fullerene formation mechanism in the carbon-clustering process.

Two lanthanide-titanium oxo clusters (LTOCs), formulated as [Eu3Ti3(μ3-O)2(μ3-OH)(CH3O)2(Ac)2(CH3OH)(tbba)12]·CH3OH (1) and [Eu6Ti8(μ3-O)13(μ2-OH)(μ3-OCH3)2(μ2-OCH3)2(H2O)(CH3OH)2(tbba)19]·Htbba·10H2O (2), were synthesized through the solvothermal reaction of 4-tert-butylbenzoate ligand, Eu(Ac)3·3H2O, and Ti(OiPr)4 in methanol. Single-crystal structural analysis reveals that 1 crystallized in the orthorhombic space group Pnn2, and 2 crystallized in the triclinic space group P1. Structurally, the core of 1 can be viewed as a coplanar unit of [Eu3Ti3(μ3-O)2(μ3-OH)]16+ formed through each μ3-O2- and μ3-OH- bridging one Ti4+ and two Eu3+ ions, while that of 2 can be viewed as two units of [Eu3Ti3(μ3-O)3(μ2-O)4(μ2-OCH3)2(CH3OH)]5+ and [Eu3Ti5(μ3-O)6(μ2-OH)(μ3-OCH3)2(H2O)(CH3OH)]14+ connected through four μ2-O units from the [Eu3Ti3(μ3-O)3(μ2-O)4(μ2-OCH3)2(CH3OH)]5+ unit to respectively coordinate two Eu3+ and two Ti4+ ions from the [Eu3Ti5(μ3-O)6(μ2-OH)(μ3-OCH3)2(H2O)(CH3OH)]14+ unit. Measurement of their luminescence properties shows that the luminescence lifetime and quantum yield are 1212 μs and 69.6% for 1 and 857 μs and 56.2% for 2. When F- was introduced into 1 in a molar ratio of F- to 1 of 1:3, its quantum yield was increased 1.3 times, and the lifetime increased from 1.2 to 1.4 ms. However, no obvious enhancement in the emission intensity was observed in 2; even the molar ratio of F- to 2 is in the range from 2 to 1/4. Investigation on the structures of 1 and 2 reveals that the luminescence lifetime and quantum yield in 1 is significantly larger than that in 2 are attributed to the vibration of the nonradiative O-H vibration groups in 1 being significantly smaller than that in 2.

A general one-step synthesis of symmetrical or unsymmetrical 1,4-di(organo)fullerenes from organo(hydro)fullerenes (RC60H) is realized by direct oxidative arylation. The new combination of catalytic trifluoromethanesulfonic acid (TfOH) and stoichiometric o-chloranil is the first to be used to directly generate an R-C60+ intermediate from common RC60H. Unexpectedly, the in situ generated R-C60+ intermediate is shown to be quite stable in whole 13C NMR spectroscopy characterization in the absence of cation quenching reagents. Because the direct oxidation of common RC60H to form the corresponding R-C60+ has never been realized, the present combination of TfOH and o-chloranil solves the challenges associated with the formation of stable RC60+ cations from common RC60H without any coordination of an R group.

No formation of bulk silver hydride has been reported. Until very recently, only a few silver nanoclusters containing hydrides have been successfully prepared. However, due to the lack of effective techniques and also poor stability of hydride-containing Ag nanoclusters, the identification of hydrides' location within Ag nanoclusters is challenging and not yet achieved, although some successes have been reported on clusters of several Ag atoms. In this work, we report a detailed structural and spectroscopic characterization of the [Ag40(DMBT)24(PPh3)8H12]2+ (Ag40H12) cluster (DMBT = 2,4-dimethylbenzenethiol). The metal framework consists of three concentric shells of Ag8@Ag24@Ag8, which can be described as (ν1-cube)@(truncated-ν3-octahedron)@(ν2-cube), respectively. The presence of 12 hydrides in each cluster was systematically identified by various techniques. Based on a detailed analysis of the structural features and 1H and 2H NMR spectra, the positions of the 12 hydrides were determined to be residing on the 12 edges of the cubic core. As a result, the electron count of the Ag40 cluster is a two-electron superatomic system instead of a 14-electron system. Moreover, based on our DFT calculations and experimental probes, it was demonstrated that the 12 hydrides play a crucial role in stabilizing both the electronic and geometric structure of the Ag40H12 cluster. The successful synthesis of stable hydride-containing Ag nanoclusters and the identification of hydride positions are expected to simulate research attention on both synthesis and application of hydride-containing Ag nanomaterials.

In regular perovskite solar cells (PSCs), the commonly used electron transport layer (ETL) is titanium oxide (TiO2). Nevertheless, the preparation of a high-quality TiO2 ETL demands an elevated-tem...

Based on the anion template and chiral ligand inducting role, two series of high-nuclearity 3 d-4 f heterometallic clusters with formulas [NO3@Ln6Cu24(μ3-OH)30(μ2-OH)3(OAc)6( R/ S-L)12(H2O)24](NO3)14· x(H2O) (Ln = Dy, x = 30 for 1a( R-L) and 1b( S-L); Ln = Tb, x = 40 for 2a( R-L) and 2b( S-L)) and (Et3NH)4[Ln6Cu12(μ3-OH)14(μ2-Cl)6Cl12( R/ S-L)12]Cl2· x(H2O) (Ln = Dy, x = 28 for 3a( R-L) and 3b( S-L); Ln = Tb, x = 33 for 4a ( R-L) and 4b( S-L); HL = ( R/ S)-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid), have been synthesized and characterized. Structural analysis reveals that the metal skeleton of compounds 1 and 2 display a Ln6Cu12 octahedral inner core encapsulated by six outer Cu2 units. In the Ln6Cu12 octahedron, 6 Ln3+ ions located at the six vertices and 12 inner Cu2+ ions located at the 12 edges of octahedron, and one NO3- locates in the center of the octahedron. The metal core of compounds 3 and 4 can be viewed as a Ln6 octahedron encapsulated by six Cu2 units. It is interesting that the different inorganic anions involved in the reaction result in the difference in the structures of 1 to 2 and 3 to 4. Circular dichroism spectra of 1-4 display obvious mirror symmetry effect at 600-800 nm of d-d transition of Cu2+, suggesting that the chirality transferred from chiral R- and S-ligand to Cu2+ ions in this system. Notably, the CD peak at the Cu2+ d-d transition position of Ln6Cu12 cluster is obviously blue-shifted compared with that of Ln6Cu24 due to the different coordinated environments of Cu2+. Magnetic studies indicate that 1a and 2a show weak ferromagnetic interactions, while 3a and 4a display antiferromagnetic interactions.

A chiral mesoporous lanthanide-based metal–organic framework (Ln-MOF) was synthesized. More importantly, its loading capacity for Mn12Ac reached 40.15 mol %, which is not only larger than that repo...

A metal–organic framework (MOF), {[Co3(ip)3(1,3-bpeb)4]·H2O}n (1), with multiple photoreactive centers, was synthesized via hydrothermal reaction of Co(II) ion with isophthalate and 1,3-bis[2-(4-py...

Photostability is a critical issue for evaluating the use of photocatalysts to realize large-scale implementation of solar energy conversion. Recently emerged ultrasmall gold (Au) clusters with distinctive physicochemical properties have been regarded as visible-light photosensitizers for photoredox catalysis, whereas the poor stability under visible-light exposure greatly restricts their photocatalytic applications. Herein, we provide a proof-of-concept study on enhancing the photostability of ultrasmall Au clusters via a combined strategy of surface engineering and interfacial modification. The photostability of Au clusters on the surface of TiO2 nanosheets with less hydroxyl group can be improved to some extent as compared to that on TiO2 nanoparticles with abundant hydroxyl groups under continuous visible-light irradiation (λ > 420 nm). Moreover, the subsequent modification of branched polyethylenimine (BPEI) between TiO2 nanosheets and Au clusters further improves their photostability upon light illumination. Consequently, the as-constructed TiO2 nanosheet-BPEI-Au cluster composites exhibit stable visible-light activity toward Cr(VI) photoreduction. It is hoped that the joint strategy via surface engineering and interfacial modification provides a facile guideline for stabilizing ultrasmall Au clusters toward targeting applications in the photoredox catalysis process.

The combustion has long been applied for industrial synthesis of carbon materials such as fullerenes as well as carbon particles (known as carbon black), but the components and structures of the carbon soot are far from being clarified. Herein, we retrieve an unprecedented hydrofullerene C66H4 from a soot of a low-pressure combustion of benzene-acetylene-oxygen. Unambiguously characterized by single-crystal X-ray diffraction, the C66H4 renders a nonclassical geometry incorporating two heptagons and two pairs of fused pentagons in a C2 v symmetry. The common vertexes of the fused pentagons are bonded with four hydrogen atoms to convert the hydrogen-linking carbon atoms from sp2 to sp3 hybridization, which together with the adjacent heptagons essentially releases the sp2-bond strains on the abutting-pentagon sites of the diheptagonal fused pentagon C66 (dihept-C66). DFT computations suggest the possibility for an in situ hydrogenation process leading to stabilization of the dihept-C66. In addition, the experiments have been carried out to study heptagon-dependent properties of dihept-C66H4, indicating the key responsibility of the heptagon for changing hydrocarbon activity and electronic properties. The present work with the unprecedented double-heptagon-containing hydrofullerene successfully isolated and identified as one of the low-pressure combustion products shows that the heptagon is a new building block for constructing fullerene products in addition to pentagons and hexagons in low-pressure combustion systems.