Accurate control of the layer number of orderly stacked 2D polymers has been an unsettled challenge in self‐assembly. Herein we describe the fabrication of a bilayer 2D supramolecular organic ...framework from a monolayer 2D supramolecular organic framework in water by utilizing the cooperative coordination of a rod‐like bipyridine ligands to zinc porphyrin subunits of the monolayer network. The monolayer supramolecular framework is prepared from the co‐assembly of an octacationic zinc porphyrin monomer and cucurbit8uril (CB8) in water through CB8‐encapsulation‐promoted dimerization of 4‐phenylpyridiunium subunits that the zinc porphyrin monomer bear. The bilayer 2D supramolecular organic framework exhibits structural regularity in both solution and the solid state, which is characterized by synchrotron small‐angle X‐ray scattering and high‐resolution transmission electron microscopic techniques. Atomic force microscopic imaging confirms that the bilayer character of the 2D supramolecular organic framework can be realized selectively on the micrometer scale.
Generation of a bilayer 2D supramolecular organic framework is realized by hierarchical assembly in water. The coordination of a rod‐like bipyridine ligand to the zinc porphyrin subunits of a monolayer supramolecular network has been utilized to selectively produce ordered bilayer supramolecular architectures with controlled thickness.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Quantum mechanical and molecular dynamics simulations have been carried out on a series of anthracene‐o‐carborane derivatives (ANT‐H, ANT‐Ph, ANT‐Me and ANT‐TMS) with rare red‐light emission in the ...solid state. The simulation of the heating process of the crystals and further comparison of the molecular structures and excited‐state properties before and after heating help us to disclose the thermochromic behavior, that is, the red‐shift emission is caused by elongation of the C1−C2 bond in the carborane moiety after heating. Thus, we believe that the molecular structure in the crystal is severely affected by heating. Transformation of the molecular conformation appears in the ANT‐H crystal with increasing temperature. More specifically, the anthracene moiety moves from nearly parallel to the C1−C2 bond to nearly perpendicular, causing the short‐wavelength emission to disappear after heating. As for the aggregation‐induced emission phenomenon, the structures and photophysical properties were investigated comparatively in both the isolated and crystal states; the results suggested that the energy dissipation in crystal surroundings was greatly reduced through hindering structure relaxation from the excited to the ground state. We expect that discussion of the thermochromic behavior will provide a new analysis perspective for the molecular design of o‐carborane derivatives.
When the heat is on: A series of anthracene‐o‐carborane derivatives with red‐light aggregation‐induced emission has been studied theoretically. The changes in bond length and dihedral angle result from alteration of the crystal stacking structure after heating, and the thermochromic behavior in crystal is ascribed to the elongation of bond length.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Radiation dosimeters displaying conspicuous response of irradiance are highly desirable, owing to the growing demand of monitoring high-energy radiation and environmental exposure. Herein, we present ...a case of dosimetry based on a discrete nanocluster, Th
(OH)
(O)
(H
O)
(TPC)
(HCOO)
∙4DMF∙H
O (Th-SINAP-100), by judiciously incorporating heavy Th
polynuclear centers as radiation attenuator and organic linkers as photo-responsive sensor. Interestingly, dual-module photochromic transitions upon multiple external stimuli including UV, β-ray, and γ-ray are integrated into this single material. The striking color change, and more significantly, the visible color transition of luminescence in response to accumulating radiation dose allow an on-site quantitative platform for naked-eye detection of ionization radiations over a broad range (1-80 kGy). Single crystal X-ray diffraction and density functional theory calculations reveal that the dual-module photochromism can be attributed to the π(TPC) → π*(TPC) intermolecular charge transfer driven by enhanced π-π stacking interaction between the adjacent TPC moieties upon irradiation.
Highlights
Recent progress of active materials in supercapacitors synthesized by electrochemical techniques is reviewed.
Electrochemically synthesized nanostructures of various dimensions, ...compositions, and electrochemical properties are discussed.
The advantages and challenges of electrochemical technologies in preparing nano-/microstructured materials for electrochemical energy storage devices are summarized.
The article reviews the recent progress of electrochemical techniques on synthesizing nano-/microstructures as supercapacitor electrodes. With a history of more than a century, electrochemical techniques have evolved from metal plating since their inception to versatile synthesis tools for electrochemically active materials of diverse morphologies, compositions, and functions. The review begins with tutorials on the operating mechanisms of five commonly used electrochemical techniques, including cyclic voltammetry, potentiostatic deposition, galvanostatic deposition, pulse deposition, and electrophoretic deposition, followed by thorough surveys of the nano-/microstructured materials synthesized electrochemically. Specifically, representative synthesis mechanisms and the state-of-the-art electrochemical performances of exfoliated graphene, conducting polymers, metal oxides, metal sulfides, and their composites are surveyed. The article concludes with summaries of the unique merits, potential challenges, and associated opportunities of electrochemical synthesis techniques for electrode materials in supercapacitors.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Layered oxide cathodes such as Ni‐rich ternary and Li‐rich layered cathode materials have been widely used for lithium‐ion batteries owing to their excellent Li+ transport properties, high energy ...density, and relatively low cost. However, such layered cathode materials synthesized by high‐temperature sintering face inherent issues such as low structural stability, irreversible migration of transition metal ions, and irreversible redox reactions of oxygen anions. To make a breakthrough from the perspective of material synthesis, a new ion‐exchange synthesis has emerged in recent years, which is a promising strategy for synthesis of Li‐ion cathodes. Herein, the fundamentals of ion‐exchange synthesis and their implications in layered oxide cathodes for lithium‐ion batteries is presented. Specifically, ion‐exchange synthesis and mechanisms of ion exchange are introduced in detail, followed by a discussion of the reduction of synthetic temperature, the synthesis of novel crystal structures, the inhibited migration of transition metal ions, the increased reversibility of anionic redox, and the optimized surface reconstruction. Finally, a summary and outlook is provided for ion‐exchange synthesis of layered oxide cathodes for lithium‐ion batteries. It is anticipated that this ion‐exchange synthesis will facilitate the commercialization of high‐performance cathode materials for next generation Li‐ion batteries.
Ion exchange offers a new way to prepare high‐performance cathode materials from the perspective of materials synthesis. In this review, the mechanisms of ion exchange are presented and its application to the synthesis of layered cathode materials for lithium‐ion batteries are discussed. The outlook for ion‐exchange synthesis of layered cathode materials is also provided.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The gestational weight gain (GWG) range of Chinese women with gestational diabetes mellitus (GDM) remains unclear. Our objective was to identify the ranges of GWG in Chinese women with GDM and to ...investigate the associations between prepregnancy body mass index (BMI), GWG and maternal-infant adverse outcomes. Cases of GDM women who delivered singletons from 2013 to 2018 in a public hospital were collected. Logistic regression analysis was used to assess the joint effects of prepregnancy BMI and GWG on maternal-infant adverse outcomes. Ultimately, 14,578 women were collected. The ranges of GWG in Chinese women with GDM were different from the National Academy of Medicine's (NAM) recommendation. The ranges of GWG of Chinese women with GDM in the underweight, normal weight, overweight and obese groups were 5.95-21.95 kg, 4.23-21.83 kg, 0.88-21.12 kg and - 1.76 to 19.95 kg, respectively. The risks of large for gestational age (LGA), macrosomia and caesarean delivery were significantly increased with the increasing prepregnancy BMI. Furthermore, the risks of LGA, macrosomia and caesarean delivery were significantly higher in the normal weight group with a GWG higher than the NAM recommendation. Similarly, in the overweight group with a GWG higher than the NAM recommendation, the risks of LGA were significantly higher, while the risks of macrosomia were significantly lower. Overall, we determined the range of GWG in different prepregnancy BMI groups. And GDM women with high prepregnancy BMI and excessive GWG were associated with the higher risks of maternal-infants adverse outcomes in China.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The overlapping metabolic reprogramming of cancer and immune cells is a putative determinant of the antitumor immune response in cancer. Increased evidence suggests that cancer metabolism not only ...plays a crucial role in cancer signaling for sustaining tumorigenesis and survival, but also has wider implications in the regulation of antitumor immune response through both the release of metabolites and affecting the expression of immune molecules, such as lactate, PGE
, arginine, etc. Actually, this energetic interplay between tumor and immune cells leads to metabolic competition in the tumor ecosystem, limiting nutrient availability and leading to microenvironmental acidosis, which hinders immune cell function. More interestingly, metabolic reprogramming is also indispensable in the process of maintaining self and body homeostasis by various types of immune cells. At present, more and more studies pointed out that immune cell would undergo metabolic reprogramming during the process of proliferation, differentiation, and execution of effector functions, which is essential to the immune response. Herein, we discuss how metabolic reprogramming of cancer cells and immune cells regulate antitumor immune response and the possible approaches to targeting metabolic pathways in the context of anticancer immunotherapy. We also describe hypothetical combination treatments between immunotherapy and metabolic intervening that could be used to better unleash the potential of anticancer therapies.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The emergence and development of radical luminescent materials is a huge breakthrough toward high-performance organic light-emitting diodes (OLEDs) without spin-statistical limits. Herein, we design ...a series of radicals based on tris(2,4,6-trichlorophenyl)methyl (TTM) by combining skeleton-engineering and periphery-engineering strategies, and present some insights into how different chemical modifications can modulate the chemical stability and luminescence properties of radicals by quantum chemistry methods. Firstly, through the analysis of the geometric structure changes from the lowest doublet excited state (D
1
) to the doublet ground state (D
0
) states, the emission energy differences between the BN orientation isomers are explained, and it is revealed that the radical with a smaller dihedral angle difference can more effectively suppress the geometric relaxation of the excited states and bring a higher emission energy. Meanwhile, a comparison of the excited state properties in different radicals can help us to disclose the luminescence behavior, that is, the enhanced luminescent intensity of the radical is caused by the intensity borrowing between the charge transfer (CT) state and the dark locally excited (LE) state. In addition, an efficient algorithm for calculating the internal conversion rate (
k
IC
) is introduced and implemented, and the differences in
k
IC
values between designed radicals are explained. More specifically, the delocalization of hole and electron wave functions can reduce nonadiabatic coupling matrix elements (NACMEs), thus hindering the non-radiative decay process. Finally, the double-regulation of chemical stability and luminescence properties was realized through the synergistic effect of skeleton-engineering and periphery-engineering, and to screen the excellent doublet emitter (
BN-41-MPTTM
) theoretically.
A series of radicals based on tris(2,4,6-trichlorophenyl)methyl (TTM) were theoretically designed and evaluated by combining skeleton-engineering and periphery-engineering strategies.
South China belongs to the northern geographic branch of the Australasian strewn field (AASF) of tektites and microtektites, and this area is assumed to be part of the uprange region of the putative ...impactor trajectory that formed the yet undiscovered source crater. Ferromagnetic minerals in impact glass may record the magnetization process and thermal history of impact melt, but the possible identity of ferromagnetic minerals in AASF tektites from South China is elusive. Here, we perform a rock magnetism and crystallography study of iron‐sulfur spherules in Muong Nong‐type tektites from South China, revealing abundant single‐domain and pseudo single‐domain nano‐grains of magnetite within the spherules. This result is consistent with the detection of magnetic signals caused by single‐domain and pseudo single‐domain magnetite in these samples. Compared to the large value ranges of magnetic properties of tektites in the entire strewn field, individual specimens of both Muong Nong‐type and single splash‐form tektites have relatively homogeneous magnetic properties in terms of magnetic susceptibility, natural remanent magnetization (NRM), saturation isothermal remanent magnetization (SIRM) and NRM/SIRM ratio. The results indicate that the impact melt that formed each tektite specimen experienced similar thermal history, and most AASF tektites from South China were cooled in an ambient magnetic field that is the same order of magnitude as the Earth's magnetic field.
Plain Language Summary
The vast Australasian strewn field (AASF) of tektites and microtektites was formed at 0.788 million years ago by an enormous impact that may have occurred somewhere in the Indochina Peninsula. The magnetic properties of tektites may record the cooling history and post‐ejection magnetization process of the tektite‐forming melt, which could provide additional insights into the possible impact location. AASF tektites from South China are a unique portion of this strewn field regarding the hypothesized impactor trajectory, and our earlier rock magnetism study suggested that tektites in this region exhibit systematically different magnetic properties. This work performs detailed geochemical and crystallographic analyses for iron‐sulfur spherules in Muong Nong‐type tektites from South China, revealing abundant nano‐sized magnetite grains in the interior that are consistent with being single‐domain and pseudo single‐domain magnetite. This result is consistent with the detection of magnetic signals caused by single‐domain and pseudo single‐domain magnetite in these samples. Most tektites from South China have relatively homogeneous magnetic properties in the interior. Their paleointensity has the same order of magnitude compared to the Earth's magnetic field.
Key Points
Nano‐sized euhedral magnetite grains were discovered in Muong Nong‐type tektites
Individual tektite specimens from South China usually exhibit relatively homogenous magnetic properties
Australasian tektites in South China have been magnetized in an Earth‐strength magnetic field
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
High-performance luminescent radical-based materials are emerging and are in demand for application in organic light-emitting diodes (OLEDs). Herein, quantum chemistry methods are employed to ...investigate a series of donoracceptor (DA) type monoradical molecules based on the tris(2,4,6-trichlorophenyl)methyl (TTM) acceptor and triarylamine (TPA) donor. The major factors affecting the device performance of the monoradical molecules, including thermodynamic stability, excited state characteristics and luminescence properties, are taken into consideration. The introduction of donor fragments can help to tune the luminescent properties of the monoradical molecule, and furthermore, the electron donating abilities of donor fragments, revealed by molecular Mulliken electronegativity, are negatively associated with both the stability and photoluminescence quantum yield (PLQY). The hybrid transition characteristic formed by the combination of charge transfer (CT) and localized excitation (LE) makes a significant contribution to the luminescence intensity of the monoradical molecules. Comparative analyses can lead us to conclude that monoradical molecules
1
,
2
,
3
,
4
,
6
and
8
possess more significant stability and photoluminescence efficiency, and are expected to become high-performance luminescent materials. Finally, our investigations show that in order to enhance the thermodynamic stability and PLQY, it should be appropriately considered to weaken the electron donating ability of donor fragments in the TTM-based D-A type of monoradical molecules by rational chemical modifications.
Spin-unrestricted DFT and spin-unrestricted TDDFT calculations were performed to systematically investigate the correlation between the electron donating ability of donors and photophysical properties in D-A luminescent radicals.
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