Dual-Templating Approaches to Soybeans Milk-Derived Hierarchically Porous Heteroatom-Doped Carbon Materials for Lithium-Ion Batteries

Biomass derived carbon materials are widely available, cheap and abundant resources. The application of these materials as electrodes for rechargeable batteries shows great promise. To further explore their applications in energy storage fields, the structural design of these materials has been investigated. Hierarchical porous heteroatom-doped carbon materials (HPHCs) with open three-dimensional (3D) nanostructure have been considered as highly efficient energy storage materials. In this work, biomass soybean milk is chosen as the precursor to construct N, O co-doped interconnected 3D porous carbon framework via two approaches by using soluble salts (NaCl/Na₂CO₃ and ZnCl₂/Mg₅(OH)₂(CO₃)₄, respectively) as hard templates. The electrochemical results reveal that these structures were able to provide a stable cycling performance (710 mAh ⋅ g⁻¹ at 0.1 A ⋅ g⁻¹ after 300 cycles for HPHC-a, and 610 mAh ⋅ g⁻¹ at 0.1 A ⋅ g⁻¹ after 200 cycles for HPHC-b) in Li-ion battery and Na-ion storage (210 mAh ⋅ g⁻¹ at 0.1 A ⋅ g⁻¹ after 900 cycles for HPHC-a) as anodes materials, respectively. Further comparative studies showed that these improvements in HPHC-a performance were mainly due to the honeycomb-like structure containing graphene-like nanosheets and high nitrogen content in the porous structures. This work provides new approaches for the preparation of hierarchically structured heteroatom-doped carbon materials by pyrolysis of other biomass precursors and promotes the applications of carbon materials in energy storage fields.     

Polyoxometalate-Incorporated CuI-Resorcin[4]arene Metal-Organic Complexes as Heterogeneous Catalysts for Catalytic Oxidation of Mustard Gas Simulant

Exploring efficient heterogeneous catalysts for catalytic oxidation of chemical warfare agents (CWAs) is highly desired. As a class of discrete anionic metal oxide clusters, polyoxometalates (POMs) provide abundant catalytic active sites, thus resulting their rich redox properties. Here, a family of known POM-incorporated Cu^I-resorcin[4]arene metal-organic complexes, namely, [Cu₄(TPTR4A)₂][PW₁₂O₄₀](OH) ⋅ 0.5DMA ⋅ 5H₂O ( Cu - PW ), [Cu₄(TPTR4 A)₂][PMo₁₂O₄₀](OH) ⋅ 2DMA ⋅ H₂O ( Cu - PMo ) and [Cu₄(TPTR4A)₂][SiW₁₂O₄₀] ⋅ 2.5DMA ( Cu - SiW ) were utilized as catalysts to promote the oxidation of 2-chloroethyl ethyl sulfide (CEES). Strikingly, compared to the novel compound [Cu₃Cl₆(TPTR4A)(DMA)] ⋅ CH₃CH₂OH (defined as Cu - T ), the three complexes exhibited excellent stability, indicating that the integration of POMs and metal–organic units could improve the stability of the compounds. Moreover, Cu - PMo and Cu - PW showed higher activities for the catalytic oxidation of CEES to CEESO with selectivities both of 99 %.     

Co-Intercalation of Dual Charge Carriers in Metal-Ion-Confining Layered Vanadium Oxide Nanobelts for Aqueous Zinc-Ion Batteries

Vanadium-based oxides with high theoretical specific capacities and open crystal structures are promising cathodes for aqueous zinc-ion batteries (AZIBs). In this work, the confined synthesis can insert metal ions into the interlayer spacing of layered vanadium oxide nanobelts without changing the original morphology. Furthermore, we obtain a series of nanomaterials based on metal-confined nanobelts, and describe the effect of interlayer spacing on the electrochemical performance. The electrochemical properties of the obtained Al_2.65V₆O₁₃ ⋅ 2.07H₂O as cathodes for AZIBs are remarkably improved with a high initial capacity of 571.7 mAh ⋅ g⁻¹ at 1.0 A g⁻¹. Even at a high current density of 5.0 A g⁻¹, the initial capacity can still reach 205.7 mAh g⁻¹, with a high capacity retention of 89.2 % after 2000 cycles. This study demonstrates that nanobelts confined with metal ions can significantly improve energy storage applications, revealing new avenues for enhancing the electrochemical performance of AZIBs.     

Pseudocapacitive Lithium Storage of Cauliflower-Like CoFe2O4 for Low-Temperature Battery Operation

Binary transition-metal oxides (BTMOs) with hierarchical micro–nano-structures have attracted great interest as potential anode materials for lithium-ion batteries (LIBs). Herein, we report the fabrication of hierarchical cauliflower-like CoFe₂O₄ (cl-CoFe₂O₄) via a facile room-temperature co-precipitation method followed by post-synthetic annealing. The obtained cauliflower structure is constructed by the assembly of microrods, which themselves are composed of small nanoparticles. Such hierarchical micro–nano-structure can promote fast ion transport and stable electrode–electrolyte interfaces. As a result, the cl-CoFe₂O₄ can deliver a high specific capacity (1019.9 mAh g⁻¹ at 0.1 A g⁻¹), excellent rate capability (626.0 mAh g⁻¹ at 5 A g⁻¹), and good cyclability (675.4 mAh g⁻¹ at 4 A g⁻¹ for over 400 cycles) as an anode material for LIBs. Even at low temperatures of 0 °C and −25 °C, the cl-CoFe₂O₄ anode can deliver high capacities of 907.5 and 664.5 mAh g⁻¹ at 100 mA g⁻¹, respectively, indicating its wide operating temperature. More importantly, the full-cell assembled with a commercial LiFePO₄ cathode exhibits a high rate performance (214.2 mAh g⁻¹ at 5000 mA g⁻¹) and an impressive cycling performance (612.7 mAh g⁻¹ over 140 cycles at 300 mA g⁻¹) in the voltage range of 0.5–3.6 V. Kinetic analysis reveals that the electrochemical performance of cl-CoFe₂O₄ is dominated by pseudocapacitive behavior, leading to fast Li⁺ insertion/extraction and good cycling life.     

Solvent-tuned polyoxometalate-based supramolecular hybrids constructed from different metal-organic motifs: Various structures and adsorption properties for dyes

Three polyoxometalate-based supramolecular hybrids with different metal-organic motifs have been synthesized by tuning the solvents, which show various adsorption activities for different organic dyes.     

Spin Crossover Behavior of FeII Complexes Bridged by Thiophene-Functionalized Triazole Ligands with Different Sizes and Rigidities

Four thiophene functionalized triazole ligands (L1=4-(thenyl)-1,2,4-triazole, L2=4-(thiophene ethyl)-1,2,4-triazole, L3=N-Thiophenylidene-4H-1,2,4-triazole-4-amine, and L4=(4-[(E)-2-(5-sulfothiophene)vinyl]-1,2,4-triazole) were synthesized. These ligands have different lengths and rigidities, while ligand L4 has a sulfonic acid group that can form a hydrogen bond. Five 1D Fe^II chain complexes were synthesized: [Fe(L1)₃](X)₂ ⋅ nH₂O [X=BF₄⁻, n=1.5 ( C1 ); X=ClO₄⁻, n=1 ( C2 )], [Fe(L2)₃](BF₄)₂ ⋅ 1.5H₂O ( C3 ); [Fe(L3)₃](X)₂ ⋅ nH₂O [X=BF₄⁻, n=2 ( C4 ); X=ClO₄⁻, n=2.5 ( C5 )]. The results of temperature-dependent magnetic susceptibility reveal that complexes C1 , C2 , and C3 experienced the transition between two spin states. And C4 and C5 maintain high spin states at all temperature ranges. Binuclear complex [Fe₂(L3)₅(SCN)₄] ( C6 ) and mononuclear material [Fe(L4)₂(H₂O)₄] ⋅ 2H₂O ( C7 ), these two zero-dimensional molecules were also synthesized. They all display weak antiferromagnetic exchange coupling and a high spin state in the whole process.     

Synthesis,Structure, and Properties of Two Supramolecular Compounds Based on Silicotungstic Acid and Transition Metal(II) Coordinated Isonicotinic Acid

Two compounds, namely [Cd(HINA)₂(µ₂‐H₂O)(H₂O)₂]₂[SiW₁₂O₄₀]·6H₂O ( 1 ) and [Co(HINA)₃(H₂O)₃][Co(HINA)₂(H₂O)₄][SiW₁₂O₄₀]·2H₂O ( 2 ), have been synthesized from the aqueous mixture containing H₄SiW₁₂O₄₀, isonicotinic acid (HINA), and M(CH₃COO)₂ (M=Cd and Co). The compounds have been characterized by elemental analysis, IR spectroscopy, TG analysis, and single‐crystal X‐ray diffraction. The dinuclear coordinated cadmium units in compound 1 are linked to form 2D layer parallel to ab plane through π‐π interactions and hydrogen bonds. Compound 2 contains two different types of coordinated metal cations, [Co(HINA)₃(H₂O)₃]²⁺ and [Co(HINA)₂(H₂O)₄]²⁺, which construct 2D layer along bc plane through π‐π interactions and hydrogen bonds. In both compounds, the Keggin anions are located inside the channels and cavities formed from stack of the coordinated metal cations, which further achieve the 3D supramolecular structure through hydrogen bonds. The luminescent property of compounds 1 and 2 has been investigated.     

Slow Magnetic Relaxation,Antiferromagnetic Ordering,and Metamagnetism in MnII(H2dapsc)-FeIII(CN)6 Chain Complex with Highly Anisotropic Fe-CN-Mn Spin Coupling

Reactions of [Mn(H₂dapsc)Cl₂] ⋅ H₂O (dapsc=2,6- diacetylpyridine bis(semicarbazone)) with K₃[Fe(CN)₆] and (PPh₄)₃[Fe(CN)₆] lead to the formation of the chain polymeric complex {[Mn(H₂dapsc)][Fe(CN)₆][K(H₂O)_3.5]}_n ⋅ 1.5n H₂O ( 1 ) and the discrete pentanuclear complex {[Mn(H₂dapsc)]₃[Fe(CN)₆]₂(H₂O)₂} ⋅ 4 CH₃OH ⋅ 3.4 H₂O ( 2 ), respectively. In the crystal structure of 1 the high-spin [Mn^II(H₂dapsc)]²⁺ cations and low-spin hexacyanoferrate(III) anions are assembled into alternating heterometallic cyano-bridged chains. The K⁺ ions are located between the chains and are coordinated by oxygen atoms of the H₂dapsc ligand and water molecules. The magnetic structure of 1 is built from ferrimagnetic chains, which are antiferromagnetically coupled. The complex exhibits metamagnetism and frequency-dependent ac magnetic susceptibility, indicating single-chain magnetic behavior with a Mydosh-parameter φ=0.12 and an effective energy barrier (U_eff/k_B) of 36.0 K with τ₀=2.34×10⁻¹¹ s for the spin relaxation. Detailed theoretical analysis showed highly anisotropic intra-chain spin coupling between [Fe^III(CN)₆]³⁻ and [Mn^II(H₂dapsc)]²⁺ units resulting from orbital degeneracy and unquenched orbital momentum of [Fe^III(CN)₆]³⁻ complexes. The origin of the metamagnetic transition is discussed in terms of strong magnetic anisotropy and weak AF interchain spin coupling.     

Syntheses and Structures of New Rare‐Earth Metal Tetracyanidoborates

Six new rare‐earth metal tetracyanidoborates were prepared and characterized by single‐crystal X‐ray diffraction. Crystals of these salts contain co‐crystallized solvent molecules, such as water, acetone, ethanol, or diethyl ether. In [La(EtOH)₃(H₂O)₂{B(CN)₄}₃] ( 1 ), [La(EtOH)(H₂O)₄{B(CN)₄}₃] · Et₂O ( 2 ), and [Y(EtOH)(H₂O)₄{B(CN)₄}₃] · EtOH ( 6 ) the tetracyanidoborate anions are all or in part bonded to the RE³⁺ ions, whereas in [Pr(H₂O)₉][B(CN)₄]₃ · (CH₃)₂CO ( 3 ), [Er(H₂O)₈][B(CN)₄]₃ · (CH₃)₂CO ( 4 ), and [Lu(EtOH)(H₂O)₇][B(CN)₄]₃ · EtOH · 0.5H₂O ( 5 ) the [B(CN)₄]^– anions are not coordinated to the central metal atoms. Only in 1 , one of the three crystallographically independent [B(CN)₄]^– anions acts as a bridging ligand.     

Coordination-Modulated Metal Tetrathiafulvalene Octacarboxylate Frameworks for High-Performance Lithium-Ion Battery Anodes

Modulation of the ligands and coordination environment of metal–organic frameworks (MOFs) has been an effective and relatively unexplored avenue for improving the anode performance of lithium-ion batteries (LIBs). In this study, three MOFs are synthesized, namely, M₄(o-TTFOB)(bpm)₂(H₂O)₂ (where M is Mn, Zn, and Cd; o-H₈TTFOB is ortho-tetrathiafulvalene octabenzoate; and bpm is 2,2′-bipyrimidine), based on a new ligand o-H₈TTFOB with two adjacent carboxylates on one phenyl, which allows us to establish the impact of metal coordination on the performance of these MOFs as anode materials in LIBs. Mn-o-TTFOB and Zn-o-TTFOB, with two more uncoordinated oxygen atoms from o-TTFOB⁸⁻, show higher reversible specific capacities of 1249 mAh g⁻¹ and 1288 mAh g⁻¹ under 200 mA g⁻¹ after full activation. In contrast, Cd-o-TTFOB shows a reversible capacity of 448 mAh g⁻¹ under the same condition due to the lack of uncoordinated oxygen atoms. Crystal structure analysis, cyclic voltammetry measurements of the half-cell configurations, and density functional theory calculations have been performed to explain the lithium storage mechanism, diffusion kinetics, and structure-function relationship. This study demonstrates the advantages of MOFs with high designability in the fabrication of LIBs.     

Anomalous Stoichiometry and Antiferromagnetic Ordering for the Extended Hydroxymanganese(II) Cubes/Hexacyanometalate-Based 3D-Structured [MnII4(OH)4][MnII(CN)6](OH2)6⋅H2O

The reaction of Mn^II(O₂CMe)₂ and NaCN or LiCN in water forms a light green insoluble material. Structural solution and Rietveld refinement of high-resolution synchrotron powder diffraction data for this unprecedented, complicated compound of previously unknown composition revealed a new alkali-free ordered structural motif with [Mn^II₄(μ₃-OH)₄]⁴⁺ cubes and octahedral [Mn^II(CN)₆]⁴⁻ ions interconnected in 3D by Mn^II-N≡C-Mn^II linkages. The composition is {[Mn^II(OH₂)₃][Mn^II(OH₂)]₃}(μ₃-OH)₄][Mn^II(μ-CN)₂(CN)₄] ⋅ H₂O=[Mn^II₄(μ₃-OH)₄(OH₂)₆][Mn^II(μ-CN)₂(CN)₄] ⋅ H₂O, which is further simplified to [Mn₄(OH)₄][Mn(CN)₆](OH₂)₇ ( 1 ). 1 has four high-spin (S=5/2) Mn^II sites that are antiferromagnetically coupled within the cube and are antiferromagnetically coupled to six low-spin (S=1/2) octahedral [Mn^II(CN)₆]⁴⁻ ions. Above 40 K the magnetic susceptibility, χ(T), can be fitted to the Curie–Weiss expression, χ ∝(T−θ)⁻¹, with θ=−13.4 K, indicative of significant antiferromagnetic coupling and 1 orders as an antiferromagnet at T_c=7.8 K.     

Complexation and Versatile Reactivity of a Highly Lewis Acidic Cationic Mg Complex with Alkynes and Phosphines

[(BDI)Mg⁺][B(C₆F₅)₄⁻] ( 1 ; BDI=CH[C(CH₃)NDipp]₂; Dipp=2,6-diisopropylphenyl) was prepared by reaction of (BDI)MgnPr with [Ph₃C⁺][B(C₆F₅)₄⁻]. Addition of 3-hexyne gave [(BDI)Mg⁺ ⋅ (EtC≡CEt)][B(C₆F₅)₄⁻]. Single-crystal X-ray analysis, NMR investigations, Raman spectra, and DFT calculations indicate a significant Mg-alkyne interaction. Addition of the terminal alkynes PhC≡CH or Me₃SiC≡CH led to alkyne deprotonation by the BDI ligand to give [(BDI-H)Mg⁺(C≡CPh)]₂ ⋅ 2 [B(C₆F₅)₄⁻] ( 2 , 70 %) and [(BDI-H)Mg⁺(C≡CSiMe₃)]₂ ⋅ 2 [B(C₆F₅)₄⁻] ( 3 , 63 %). Addition of internal alkynes PhC≡CPh or PhC≡CMe led to [4+2] cycloadditions with the BDI ligand to give {Mg⁺C(Ph)=C(Ph)C[C(Me)=NDipp]₂}₂ ⋅ 2 [B(C₆F₅)₄⁻] ( 4 , 53 %) and {Mg⁺C(Ph)=C(Me)C[C(Me)=NDipp]₂}₂ ⋅ 2 [B(C₆F₅)₄⁻] ( 5 , 73 %), in which the Mg center is N,N,C-chelated. The (BDI)Mg⁺ cation can be viewed as an intramolecular frustrated Lewis pair (FLP) with a Lewis acidic site (Mg) and a Lewis (or Brønsted) basic site (BDI). Reaction of [(BDI)Mg⁺][B(C₆F₅)₄⁻] ( 1 ) with a range of phosphines varying in bulk and donor strength generated [(BDI)Mg⁺ ⋅ PPh₃][B(C₆F₅)₄⁻] ( 6 ), [(BDI)Mg⁺ ⋅ PCy₃][B(C₆F₅)₄⁻] ( 7 ), and [(BDI)Mg⁺ ⋅ PtBu₃][B(C₆F₅)₄⁻] ( 8 ). The bulkier phosphine PMes₃ (Mes=mesityl) did not show any interaction. Combinations of [(BDI)Mg⁺][B(C₆F₅)₄⁻] and phosphines did not result in addition to the triple bond in 3-hexyne, but during the screening process it was discovered that the cationic magnesium complex catalyzes the hydrophosphination of PhC≡CH with HPPh₂, for which an FLP-type mechanism is tentatively proposed.     

Polyoxometalate‐Based Entangled Coordination Networks Induced by an Extended Bis(triazole) Ligand

The introduction of an extended bridging bis(triazole) ligand, that is, 4,4′‐bis(1,2,4‐triazol‐1‐ ylmethyl)biphenyl (BBPTZ), into the hydrothermal reaction system containing transition metal ions and Keggin‐type polyoxometalates (POMs) led to the isolation of three new organic–inorganic hybrid entangled coordination networks, [Cu^I₂Cu^II(BBPTZ)₆][SiW₁₂O₄₀]?12 H₂O ( 1 ), [Ni(BBPTZ)₂(H₂O)][H₂SiW₁₂O₄₀]?11 H₂O ( 2 ), and [Ni₂(BBPTZ)₄(H₂O)₂][SiW₁₂O₄₀]?3 H₂O ( 3 ). All three compounds were characterized by elemental analysis, IR spectroscopy, TG analysis, powder X‐ray diffraction, and single‐crystal X‐ray diffraction. Compound 1 contains a 2‐D POM‐based metal–organic layer entangled with 1‐D ladder‐like metal–organic chains. The adjacent 2‐D networks are parallel to each other, further stacking into a 3‐D supramolecular framework with 1‐D channels. Compound 2 exhibits a 1‐D cantilever‐type loop‐containing chain. The Keggin‐type POMs act as the cantilever groups, leading to the adjacent catilever‐type chains interwaving together to form a 3‐D supramolecular open framework with two types of channels. Compound 3 possesses a 3‐D open framework based on 2‐D metal–organic undulated layer and Keggin‐type POM clusters. Three sets of such frameworks further interpenetrate with each other to form an interesting three‐fold interpenetrating framework. The photocatalytic activities of compounds 1–3 for the decomposition of methylene blue (MB) under UV light have been investigated.     

Hewettite ZnV6O16 ⋅ 8H2O with Remarkably Stable Layers and Ultralarge Interlayer Spacing for High-Performance Aqueous Zn-Ion Batteries

Aqueous Zn-ion batteries (ZIBs) are promising candidates for grid-scale energy storage because of their intrinsic safety, low-cost and high energy-intensity. Vanadium-based materials are widely used as the cathode of ZIBs, especially A₂V₆O₁₆ ⋅ nH₂O (AVO, A=NH₄⁺, Na, K). However, AVO suffers from serious dissolution, phase transformation and narrow gallery spacing (∼3 Å), leading to poor cycling stability and rate capability. Herein, we unveiled the root cause of the performance degradation in the AVO cathode and therefore developed a new high-performance cathode of ZnV₆O₁₆ ⋅ 8H₂O (ZVO) for ZIB. Through a method of ion exchange induced phase transformation, AVO was converted to hewettite ZVO with larger gallery spacing (∼6 Å) and more stable V₆O₁₆ layers. ZVO cathode thus constructed delivers a high capacity of 365 and 170 mAh g⁻¹ at 0.5 and 15 A g⁻¹, while 86 % and 70 % of its capacity are retained at 0.5 A g⁻¹ after 300 cycles and at 15 A g⁻¹ after 10000 cycles, substantially better than conventional AVO.     

Syntheses and electrochemical properties of three supramolecular architectures based on Keggin silicontungstates and different metal-organic units

Three new compounds [Mn(H₂O)₂(bimb)₂(H₃SiW₁₂O₄₀)₂](bimb)₄ (1), [Zn₂(bimb)₄(H₂O)₄][SiW₁₂O₄₀] (2), and [Ni₂(bimb)₄(H₂O)₄][SiW₁₂O₄₀] (3) (bimb = 1,3-bis(1-imidazoly)benzene) have been synthesized under the same hydrothermal reaction except for tuning the metal cations (Mn²⁺, Zn²⁺, and Ni²⁺). Structural characterizations show that the three compounds possess distinct structural motives. Compound 1 displays a supramolecular one-dimensional (1 D) chain formed by π···π interactions that occur among the almost parallel bimb ligands from adjacent [Mn(H₂O)₂(bimb)₂(SiW₁₂O₄₀)₂] dimers. Compound 2 shows a supramolecular two-dimensional (2D) layer achieved by intermolecular (C–H···O) hydrogen bondings between the Zn₂(bimb)₄ molecular loops and the SiW₁₂ anions. Compound 3 also exhibits a supramolecular 2D layer, but it is different from 2, which is generated by the π···π interactions among adjacent 1D polymeric chains. The distinct structural features of the three compounds suggest that the metal cations should play a significant role in the process of assembly. Additionally, the electrochemical properties of compounds 1–3 have been investigated, and the results indicate that compounds 1–3 possess excellent electrocatalytic activity toward reduction of both iodated and nitrite molecules.     

Synthesis, structures, and magnetic properties of carboxylate-bridged trinuclear complexes based on low-spin manganese(III)/iron(III) building blocks

Four linear trinuclear transition metal complexes have been prepared and characterized. The complexes [M^II(MeOH)₄][Fe^III(L)₂]₂·2MeOH (M = Fe (1) or Ni (2)), [Co^II(EtOH)₂(H₂O)₂][Fe^III(L)₂]₂·2EtOH (3), and [Mn^II(phen)₂][Mn^III(L)₂]₂·4MeOH (4) (H₂L = ((2-carboxyphenyl)azo)-benzaldoxime, phen = 1,10-phenanthroline) possesses a similar syn–anti carboxylate-bridged structure. The terminal Fe(III) or Mn(III) ions are low spin, and the central M(II) ions are high spin. Magnetic measurements show that antiferromagnetic interactions were present between the adjacent metal ions via the syn–anti carboxylate bridges. The antiferromagnetic coupling between low-spin Fe(III) and Ni(II) is unusual, which has been tentatively assigned to the structural distortion of Fe(III).     

A Trinuclear Cobalt–Organic Framework: Solvatochromic Sensor towards CH2Cl2, and its Derivative as an Anode of Lithium-Ion Batteries with High Performance

Here, a porous cobalt–organic framework with pillared layer structures, namely [Co₃OBA₃PTD(H₂O)₂ ⋅ 2 DMA ⋅ H₂O]_n ( 1 , H₂OBA=4,4′-oxybis(benzoic acid); PTD=6-(pyridin-4-yl)-1,3,5-triazine-2,4-diamine), was fabricated by using cobalt trinuclear nodes, low-cost carboxylic linker, and accessible nitrogen heterocyclic ligands. This compound exhibited a highly efficient solvatochromism towards CH₂Cl₂ within one minute and can be used 200 times at least. The corresponding dropper detector was assembled as a practical sensor. Meanwhile, the porous Co₃O₄ was obtained by a simple but effective annealing treatment. Electrochemical measurements confirm that this Co₃O₄ material derived from compound 1 shows high and stable lithium storage capabilities (1081.75 mA h g⁻¹ at 200 mA g⁻¹ after 115 cycles) and excellent rate properties.     

Efficient Synthesis and Properties of Single‐Crystalline [SnTe4]4− Salts

Single‐crystalline K⁺, Rb⁺, and Cs⁺ salts of the ortho‐tellurostannate anion have been prepared by a very efficient fusing/extraction/evaporation method. The resulting compounds with the general composition [A₄(H₂O)_n][SnTe₄] can be transferred into mixed H₂O/en solvates by solving the hydrates in 1,2‐diaminoethane (en) and ensuing layering by toluene. A mixed Rb⁺/Ba²⁺ salt results from a partial cation exchange of the Rb⁺ hydrate phase in solution. All hydrates react to polytellurides when exposed to air and represent useful starting materials for the synthesis of transition metal complexes with [SnTe₄]^4? groups as binary main group elemental ligands. [K₄(H₂O)_0.5][SnTe₄] ( 1 ), [Rb₄(H₂O)₂][SnTe₄] ( 2 ), [Cs₄(H₂O)₂][SnTe₄] ( 3 ), [K₄(H₂O)(en)][SnTe₄] ( 4 ), [Rb₄(H₂O)_0.67(en)_0.33][SnTe₄] ( 5 ), [Cs₄(H₂O)_0.5(en)_0.5][SnTe₄] ( 6 ), and [Rb₂Ba(H₂O)₁₁][SnTe₄] ( 7 ) were characterized by means of X‐ray diffractometry and optical absorption spectroscopy.     

Novel Hybrids Constructed from Keggin-Polyoxometalate and Mixed Copper Complex

Abstract  Two new Keggin-polyoxometalate hybrids, {[Cu₂(4,4′-bpy)₂][PW₁₀^VIW₂^VO₄₀]}[Cu₂(obpy)₂]₄ · 2 H₂O (1) and {[Cu₄(2,2′-bpy)₄(4,4′-bpy)₃][SiW₁₂O₄₀]} · 2H₂O (2) (4,4′-/2,2′-bpy = 4,4′-/2,2′-bipyridyl, Hobpy = 6-hydroxy-2,2′-bipyridyl), were hydrothermally synthesized and structurally characterized. Gillard type hydration of 2,2′-bipy is observed during the synthesis of 1, resulting in a new obpy ligand in situ. X-ray structural analyses show that 1 consists of 1D hybrid chain {[Cu₂(4,4′-bpy)₂][PW₁₀^VIW₂^VO₄₀]}_∞ and [Cu₂(obpy)₂] dimer, whereas 2 possesses 1D hybrid structure based on Keggin-type [SiW₁₂O₄₀]⁴⁻ anions and tetra-nuclear copper complexes [Cu₄(2,2′-bpy)₄(4,4′-bpy)₃]⁴⁺. Both compounds present interesting supramolecular architectures based on π–π stacking and hydrogen bonds. Graphical Abstract  Compounds {[Cu₂(4,4′-bpy)₂][PW₁₂O₄₀]}[Cu₂(obpy)₂]₄ · 2H₂O (1) and [Cu₄(2,2′-bpy)₄(4,4′-bpy)₃][SiW₁₂O₄₀] · 2H₂O (2) were hydrothermally synthesized. 1 features that the [Cu₂(obpy)₂] dimers based on in situ generated obpy ligands are stumped between the layers where 1D hybrid chain {[Cu₂(4,4′-bpy)₂][PW₁₂O₄₀]}_∞ locates, while 2 exhibits 1D chain-like structure based on anions [SiW₁₂O₄₀]⁴⁻ and tetra-copper complexes [Cu₄(2,2′-bpy)₄(4,4′-bpy)₃]⁴⁺.      

Assembly of a Supramolecular Architecture Based on Keggin POMs and Lanthanide Coordination Cations

Two new compounds based on Keggin polyoxometalates (POMs) [SiW₁₂O₄₀]⁴⁻ (SiW₁₂), [Na(H₂O)₃(H₂L)SiW₁₂O₄₀](H₂L)₂   6H₂O (1), and [Ce(H₂O)₃(HL)₂(H₂L)]₂[SiW₁₂O₄₀]₂ 10H₂O (2) (HL = C₆H₅NO₂ = isonicotinic acid), have been conventionally synthesized and characterized by routine methods. Compound 1 possesses a 1D right-handed helical structure constructed by SiW₁₂O₄₀ ⁴⁻ {SiW₁₂} and [Na(H₂O)₃(HL)] complexes. Interestingly, these right-handed helical chains are linked together via H-bonds forming a novel chiral layer. By using the similar synthesis method to that for compound 1, except for employing Ce³⁺ cations in instead of La³⁺ cations, a 3D supramolecular compound 2 based on SiW₁₂ and Ce³⁺ coordination cations has been obtained, which contains 1D channels along a axis. Additionally, the luminescence properties of 2 were studied. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.