Search

The growth of lithium dendrites and the shuttle of polysulfides in lithium metal batteries (LMBs) have hindered their development. In LMBs, the cathode and anode are separated by a separator, although this does not solve the battery's issues. The use of biomass materials is widespread for modifying the separator due to their porous structure and abundant functional groups. LMBs perform more electrochemically when lithium ions are deposited uniformly and polysulfide shuttling is reduced using biomass separators. In this review, we analyze the growth of lithium dendrite and the shuttle of polysulfide in LMBs, summarize the types of biomass separator materials and the mechanisms of action (providing mechanical barriers, promoting uniform deposition of metal ions, capturing polysulfides, shielding polysulfide). The prospect of developing new separator materials from the perspective of regulating ion transport and physical sieving efficiency as well as the application of advanced technologies such as synchrotron radiation to characterize the mechanism of action of biomass separators is also proposed. [ABSTRACT FROM AUTHOR]

We present the construction of a M2L4‐type metal‐organic nanocage featuring four endohedral Feringa's motor motifs and its adaptive encapsulation towards a C60 guest molecule. The structure of the cage, though complicated on the 1H NMR spectrum due to the adoption of mixed ligands, was unambiguously characterized with a combination of ESI‐MS, 2D DOSY, 13C NMR and particularly the SAXS technique. The molecular motor within the cage demonstrated similar photophysical properties to the uncoordinated one, indicating the motor's function was not compromised when it was anchored in such a confined nanospace. Furthermore, the nanocage showed good guest encapsulation ability towards C60, and a guest induced‐fit behavior of the cage was revealed based on the extensive SAXS analysis and molecular dynamics simulation. The adaptive motorized nanocage reported here represents one of the very few examples of integrating individual motors into a discrete nanoconfined system and offers prospects to achieve its non‐equilibrium functions. [ABSTRACT FROM AUTHOR]

We designed two near‐infrared (NIR) lanthanide complexes [(L)2‐Nd(NO3)3] (L=TPE2‐BPY for 1, TPE‐BPY for 2) by employing aggregation‐induced emission (AIE)‐active tetraphenylethylene (TPE) derivatives as sensitizers, which possessed matched energy to NdIII, prevented competitive deactivation under aggregation, even shifted the excitation window toward 600 nm by twisted intramolecular charge transfer. Furthermore, benefiting from the 4 f electron shielding effect and antenna effect, the enhanced excitation energies of the AIE‐active sensitizers by structural rigidification transferred into the inert NdIII excited state through 3LMCT, affording the first aggregation‐induced phosphorescence enhancement (AIPE)‐active discrete NIR‐emitting lanthanide complexes. As 1 equipped with more AIE‐active TPE than 2, L→Nd energy transfer efficiency in the former was higher than that in the latter under the same conditions. Consequently, the crystal of 1 exhibited one of the longest lifetimes (9.69 μs) among NdIII‐based complexes containing C−H bonds. [ABSTRACT FROM AUTHOR]

Dehydration of (S,S)‐1,2‐bis(1H‐benzo[d]imidazol‐2‐yl)ethane‐1,2‐diol (H4L) to (Z)‐1,2‐bis(1H‐benzo[d]imidazol‐2‐yl)ethenol) (H3L′) was found to be metal‐assisted, occurs under solvothermal conditions (H2O/CH3OH), and leads to [MnII4(H3L)4Cl2]Cl2⋅5 H2O⋅5 CH3OH (Mn4L4) and [MnII4(H2L′)6(μ3‐OH)]Cl⋅4 CH3OH⋅H2O (Mn4L′6), respectively. Their structures were determined by single‐crystal XRD. Extensive ESI‐MS studies on solutions and solids of the reaction led to the proposal consisting of an initial stepwise assembly of Mn4L4 from the reactants via [MnL] and [Mn2L2] below 80 °C, and then disassembly to [MnL] and [MnL2] followed by ligand modification before reassembly to Mn4L′6 via [MnL′], [MnL′2], and [Mn2L′3] with increasing solvothermal temperature up to 140 °C. Identification of intermediates [Mn4LxL′6−x] (x=5, 4, 3, 2, 1) in the process further suggested an assembly/disassembly/in situ reaction/reassembly transformation mechanism. These results not only reveal that multiple phase transformations are possible even though they were not realized in the crystalline state, but also help to better understand the complex transformation process between coordination clusters during "black‐box" reactions. [ABSTRACT FROM AUTHOR]

The square-planar monomer NiL2 ( Ni1), L=2-ethoxy-6-( N-methyl-iminomethyl)phenolate, reacts with M(H2O)6(ClO4)2, M=Ni or Co, to form heptanuclear disks [Co xNi7− x(OH)6(L)6](ClO4)2 ⋅2 CH3CN ( Co x Ni7− x, x=0-7) and the co-crystal [Co xNi7− x(OH)6L6][NiL2](ClO4)2 ⋅2 CH3CN ( Co x Ni7− x -Ni1) under ambient conditions. It has proved possible to explore the bottom-up assembly process of Co x Ni7− x and Co x Ni7− x -Ni1 in real time. The final products have been characterized by thermogravimetric analysis, IR, elemental analysis, ICP-MS, and single-crystal X-ray diffraction. Time-dependent mass spectrometry (MS) revealed the following reaction steps: Ni1→[M2L3]+→[M4(OH)2L4]2+→[M7(OH)6L6]2+. In contrast, the reaction of Ni1 with Zn2+ only reaches halfway, and crystallographic evidence indicates a butterfly structure for [Zn2Ni2(OH)2Cl2] ( Zn2Ni2), an intermediate that is difficult to isolate in the above Ni-Co series. A summation method has been used to analyze the MS of bimetallic clusters with very similar atomic masses, as is the case for Co and Ni. The results provide ample information on the distribution of Co and Ni within each cluster and their statistical distribution within selected crystals. [ABSTRACT FROM AUTHOR]

A series of highly connected metal-organic frameworks (MOFs), [Co8(O)(OH)4(H2O)4(ina)8](NO3)2 ⋅2 C2H5OH ⋅4 H2O ( 1), [Co8(O)(OH)4(H2O)4(pba)8](NO3)2 ⋅8 C2H5OH ⋅28 H2O ( 2), and [Co8(O)(OH)4(H2O)4(pbba)8](NO3)2 ⋅guest ( 3), in which ina=isonicotinate, pba=4-pyridylbenzoate, and pbba=4-(pyridine-4-yl)phenylbenzoate, is reported. These MOFs contain a new secondary building unit (SBU), with a square Co4(μ4-O) central unit having the rare μ4-O2− motif, which is decorated by the other four peripheral cobalt atoms through μ3-OH in a windmill-like shape. This SBU holds 16 divergent connecting organic ligands, pyridyl-carboxylates, to form three different frameworks. The high porosity of desolvated 2 is shown by the efficient gas absorption of N2, CO2, CH4, and H2. In addition, 1 and 2 exhibit unusual canted antiferromagnetic behavior with spin-glass-like relaxation, with blocking temperatures that are fairly high, 20 K ( 1) and 10 K ( 2), for cobalt materials. The relationship between the metal clusters and linkers has been studied, in which the size and rotational degrees of freedom of the ligands are found to control the topology, gas sorption, and magnetic properties. [ABSTRACT FROM AUTHOR]

We present the construction of a M2L4‐type metal‐organic nanocage featuring four endohedral Feringa's motor motifs and its adaptive encapsulation towards a C60 guest molecule. The structure of the cage, though complicated on the 1H NMR spectrum due to the adoption of mixed ligands, was unambiguously characterized with a combination of ESI‐MS, 2D DOSY, 13C NMR and particularly the SAXS technique. The molecular motor within the cage demonstrated similar photophysical properties to the uncoordinated one, indicating the motor's function was not compromised when it was anchored in such a confined nanospace. Furthermore, the nanocage showed good guest encapsulation ability towards C60, and a guest induced‐fit behavior of the cage was revealed based on the extensive SAXS analysis and molecular dynamics simulation. The adaptive motorized nanocage reported here represents one of the very few examples of integrating individual motors into a discrete nanoconfined system and offers prospects to achieve its non‐equilibrium functions. [ABSTRACT FROM AUTHOR]