Latest ArticlesQuinoidal π-conjugated structures, a kind of fundamental subunits for organic π-systems, may produce some intriguing optical, electronic and magnetic properties of polycyclic hydrocarbons (PHs). Herein, we report two thienothiophene-centered ladder-type polycyclic molecules (1 and 2), which possess one quinoidal thienothiophene moiety and two para-quinodimethane (p-QDM) subunits, respectively. As theoretically and experimentally studied, while 1 is a fully closed-shell molecule, 2 owns an open-shell structure along with partial contribution of tetraradical state that is induced by the resonance of p-QDM. Moreover, although 2 has a larger π-conjugated skeleton and open-shell electronic state, it exhibits larger bandgap and blue-shifted absorption. On the other hand, the reversible oxidation activity of 1 enables the preparation of its dication, and the studies on its single-crystal and aromatic structures demonstrate that its two positive charges are delocalized onto the oxygen atoms, thus achieving fully π-extended structure and near-infrared absorption. This study not only gains insight into quinoidal π-subunits, but also provides an important basis for the development of antiaromatic and open-shell π-electron materials.
As the most common pathological type of nephrotic syndrome, membranous nephropathy (MN) presents diversity in progression trends, facing severe complications. The precise discrimination of MN from healthy people, other types of nephrotic syndrome or those with therapeutic remission has always been huge challenge in clinics, not to mention comprehensive individualized monitoring relied on minimally invasive molecular detection means. Herein, we construct a functionalized pore architecture to couple with machine learning to aid all-round peptidome enrichment and data profiling from hundreds of human serum samples, and finally establish a set of defined peptide panel consisting of 12 specific feature signals. In addition to the realization of above-mentioned precise discrimination with more than 97% of sensitivity, 88% of accuracy and f1 score, the simultaneously comprehensive individualized monitoring for MN can also be achieved, including conventionally screening diagnosis, congeneric distinction and prognostic evaluation. This work greatly advances the development of peptidome data-driven individualized monitoring means for complex diseases and undoubtedly inspire more devotion into molecular detection field.
Covalent organic polymer (COP) thin film-based memristors have generated intensive research interest, but the studies are still in their infancy. Herein, by controlling the content of hydroxyl groups in the aldehyde monomer, Py-COP thin films with different electronic push-pull effects were fabricated bearing distinct memory performances, where the films were prepared by the solid-liquid interface method on the ITO substrates and further fabricated as memory devices with ITO/Py-COPs/Ag architectures. The Py-COP-1-based memory device only exhibited binary memory behavior with an ON/OFF ratio of 1:101.87. In contrast, the device based on Py-COP-2 demonstrated ternary memory behavior with an ON/OFF ratio of 1:100.6: 103.1 and a ternary yield of 55%. The ternary memory mechanism of the ITO/Py-COP-2/Ag memory device is most likely due to the combination of the trapping of charge carriers and conductive filaments. Interestingly, the Py-COPs-based devices can successfully emulate the synaptic potentiation/depression behavior, clarifying the programmability of these devices in neuromorphic systems. These results suggest that the electronic properties of COPs can be precisely tuned at the molecular level, which provides a promising route for designing multi-level memory devices.
Zinc-based batteries (ZBs) have been deemed as a potential substitute for lithium-ion batteries due to its unique advantages of abundant resources, low cost and acceptable energy density. Despite great progress in designing electrode materials has been made, the development of high-performance ZBs still remain challenges, such as the dendrite growth of zinc anode, hydrogen evolution reaction, limited electrochemical stability window, water evaporation and liquid leakage. Gel polymer electrolytes (GPEs), including hydrous GPEs with low content of active water and anhydrous GPEs without the presence of water, are proposed to avoid these problems. Furthermore, employing GPEs is conductive to fabricate flexible devices owing to the good mechanical strength. To date, most of researches focus on discovering new GPEs and exploring its application on flexible or wearable devices. Recent reviews also have outlined the polymer matrixes and advances of GPEs in various battery systems. Given this, herein, we seek to summarize the gelation mechanisms of GPEs, involving physical gel of polymer, chemical crosslinking of polymer and chemical polymerization of monomers. Peculiarly, the preparation methods are also classified. In addition, not only the features and central conundrum of GPEs are analyzed but also the corresponding strategies are discussed, contributing to design GPEs with ideal properties for high-performance ZBs.
The virtual cocrystal screening approach based on molecular electrostatic potential surface (MEPS) maps is a fast and feasible computational method to estimate the probability of cocrystal formation by calculating the difference in the interaction site pairing energies of monomers and that of their assemblies prior to experimental screening. In this paper, we report 12 cocrystal forms of temozolomide with mono-, di-, and trihydroxy benzoic acids, namely, 3-hydroxy-, 2,4-dihydroxy-, 2,5-dihydroxy-, 2,6-dihydroxy-, 3,4-dihydroxy-, and 3,4,5-trihydroxy-benzoic acids, as well as benzoic acid, as pharmaceutical coformers for the first time. 10 single crystals out of the 12 cocrystal forms were obtained and unequivocally determined by single-crystal X-ray diffraction, which clarified spatial arrangements, molecular conformations, and supramolecular synthons. MEPS further gains some insights into the sites of hydrogen bonding interactions for exploring combination patterns in these assemblies. Modulated stability of TMZ was successfully achieved by cocrystallization with these acids.
In September 2018, we proposed the cutting-edge concept of "Beyond Limits Manufacturing" (BLM). BLM technology is based on the three-dimensional inner engraving or precise outer engraving of ultra-fast laser, to invent micro/nano scale flow chips or devices, which makes it possible for the microform, integration, economy, safety, high efficiency, green and intelligence of research, development and manufacturing process, so as to realize transformational manufacturing in the era of Industry 4.0. In this paper, we reviewed the representative results we made in the field of micro/nano flow chemistry during the implementation of the BLM major project (December 2019 to August 2023), and discussed its application prospects in micro/nano flow chemistry.
Electrocatalytic synthesis of ammonia as an environment-friendly and sustainable development method has received widespread attention in recent years. Two-dimensional (2D) materials are a promising catalyst for ammonia synthesis due to their large surface area. In this work, we have constructed a series of 2D metal borides (MBenes) with transition metal (TM) defects (TMd-MBenes) and comprehensively calculated the reactivity of electrocatalytic synthesis of ammonia-based on density functional theory. The results have demonstrated that the TMd-MBenes can effectively activate nitrogen oxide (NO) and nitrogen (N2) molecules thermodynamically. Particularly interesting, the co-chemisorption of O atoms, dissociated from NO, can facilitate the spilled of the inert N2 molecules into single N atoms, which can further hydrogenate into ammonia easily with an ultralow limiting potential of 0.59 V on TMd-MnB. Our research has not only provided clues for catalyst design for experimental study but also paved the way for the industrial application of electrocatalytic ammonia synthesis.
Microbial fuel cells (MFCs) have a simple structure and excellent pollutant treatment and power generation performance. However, the slow kinetics of the oxygen reduction reaction (ORR) at the MFC cathode limit power generation. The electrochemical performance of MFCs can be improved through electrocatalysis. Thus far, metal-based catalysts have shown astonishing results in the field of electrocatalysis, enabling MFC devices to demonstrate power generation capabilities comparable to those of Pt, thus showing enormous potential. This article reviews the research progress of meta-based MFC cathode ORR catalysts, including the ORR reaction mechanism of MFC, different types of catalysts, and preparation strategies. The catalytic effects of different catalysts in MFC are compared and summarized. Before discussing the practical application and expanded manufacturing of catalysts, we summarize the key challenges that must be addressed when using metal-based catalysts in MFC, with the aim of providing a scientific direction for the future development of advanced materials.
Surface fluorination of conventional polymers can give them desirable surface properties similar to the expensive and difficult-to-process fluoropolymers. However, traditional surface fluorination techniques often require toxic reagents and special equipment. Here, we report a simple and effective polymer surface fluorination method by using safe and inexpensive perfluoro-2-methyl-3-pentanone (PFMP, C2F5C(O)CF(CF3)2) and UV irradiation. This method is applicable to various polymer materials, and generates nanometer-thick fluorinated layer on the outermost surface, significantly changing their surface properties without changing the surface morphology.