The cover picture shows polymer network trees grown from monomers’ grassland through photoinduced RAFT radical step-growth polymerization between a series of unconjugated diene monomers and bifunctional xanthate. The obtained polymer network showed the ability of postfunctionalization through controlled way and degradation, which was benefitted from RAFT polymerization. More details are discussed in the article by Zhu et al. on page 503—508.

Synthetic strategy has become a powerful tool to access POPs with desired and diverse functionalities. The inside cover picture displays one-pot Ullmann coupling reaction to synthesize a series of microporous polymers with rich N-sites, named FJU-POP-n, wherein the low-cost and non-toxic Cu(acac)₂ and environmental-friendly glycerol are employed as catalyst and solvent, respectively. Among these, FJU-POP-4 with abundant N-functional sites and suitable pore size exhibits ultra-high selective separation for C₂H₂/CH₄ (307.1, 50 : 50) at ambient conditions, the highest among the reported MOFs and POPs with nitrogen-sites as only functional species. Dynamic fixed bed breakthrough and regeneration experiments confirm structural stability and reproducibility, indicating their promising application in selective separation. More details are discussed in the article by Zhang et al. on page 514—520.

Photoinduced RAFT step-growth polymerization was expanded to a series of unconjugated diene monomers in combination with a bifunctional xanthate. The polymer network was further prepared using a trifunctional monomer, which has the ability of postfunctionalization and is degradable.

A rhodium-catalyzed denitrogenative carbonylation of 1,2,3-thiadiazole with alkynes to construct (benzo)thiochromenones is developed. Both terminal and internal alkynes were compatible in this [3+2+1] cycloaddition, affording a broad range of poly-substituted thiochromenones.

Herein, a series of POPs with abundant N-functional sites were synthesized using efficient one-pot Ullmann coupling reaction, which exhibit ultra-high selective C₂H₂/CH₄ separation at ambient conditions. Furthermore, dynamic fixed bed breakthrough experiments exhibit that C₂H₂/CH₄ mixtures can be effectively separated by the activated FJU-POP-n.

Herein, a heterometal substitution strategy was employed to construct two crystalline Al₇Ni₂ compounds. Thereinto, benzyl alkoxides protected compound features high stability and can be used as an effective catalyst in aldol condensation reaction.

Two new sky-blue luminescent molecules comprised of electron acceptor of benzophenone and electron donors of spiro[acridine-9,9'-fluorene] and carbazole are designed and synthesized, which exhibit distinct merits of aggregation-induced delayed fluorescence with high solid-state photoluminescence quantum yields, balanced bipolar carrier transport, high horizontal dipole ratios and outstanding external quantum efficiencies.

Proteus mirabilis and Proteus vulgaris are zoonotic pathogens which can cause public health disease. Developing vaccine against these pathogens is urgently required. Herein, we describe the first synthesis of their common O-antigen. Glycan microarray analysis revealed that hexasaccharide 2 and nonasaccharide 3 strongly bind with the IgG antibodies, which is highly valuable for further immunological investigation in synthetic carbohydrate-based vaccine development.

Nature is an inspiring resource for chemists to exploit uncharted chemical spaces. Enzymes in nature are characteristic of high efficiency and exquisite stereocontrol under rather mild conditions. Not surprisingly, chemists have a long history in developing new catalysts by learning from and imitating the natural enzymes. This review summarizes our long-standing efforts in developing bio-inspired small molecular catalysis. These were categorized according to the employed strategies: 1) bi-/multi-functional strategy for the bio-inspired chiral primary amine catalyst; 2) cofactor strategy for bio-inspired ortho-quinone catalyst; 3) intermediate strategy for chiral latent carbocation catalysis based on natural carbocation process. Each section includes brief introduction of the biological origin, design of catalyst, development of methodology as well as the underlying mechanistic insights.

This review summarized the recent advance in the applicability of G-quadruplexes (G4s) as antiviral targets, therapeutic agents and diagnostic tools for coronavirus disease 2019 (COVID-19). Meanwhile, some challenges and perspectives were also presented, looking forward to advancing the G4s for COVID-19 therapy and diagnosis.

This review focuses on recently developed strategies to induce NPs self-assembly at the LLI and discuss the latest research progress on sensitive and reliable SERS analysis in practical applications. Finally, some perspectives are highlighted in the further development of the efficient methods to enhance the plasmonic properties and more practical SERS sensors for practical applications.

In this review, three main strategies for achieving single-atom catalysts (SACs) with excellent intrinsic activity in the context of the oxygen reduction reaction (ORR) mechanism are involved including the modulation of coordination environments, the construction of intrinsic defects, and the introduction of dual active sites. And discussions to improve the loading and utilization of active sites are given. This timely review may provide inspiration and reference for the future research of developing advanced SACs for ORR.

In this review, the effects of environmental manufacturing on perovskite thin films are summarized, and the latest progress, large-area fabrication, and appropriate strategies in the preparation of stable perovskite solar cells under environmental conditions are discussed. We hope that this summary will provide scientists with informative knowledge in relevant directions and stimulate new thoughts and ideas.

The inside back cover picture showed the liquid-liquid interface (LLI) self-assembly structure as a new substrate for analytical sensing. There were two methods to promote self-assembly at the LLI. On the one hand, strategies for promoting assembly of NPs at the LLI have been developed through the addition of chemical modifiers, promoters, or external voltage. On the other hand, in order to avoid the potential interferences of chemical promoters, shaking organic solution and aqueous solution was proposed as an alternative way to form uniform NPs array at the LLI based on emulsification mechanism. Such strategies to fabricate uniform SERS substrate based on the LLI were demonstrated to be efficient to improve the reproducibility of SERS analysis, which are potentially applicable for practical applications. More details are discussed in the article by Zhang et al. on page 569—580.

Proteus mirabilis and Proteus vulgaris are zoonotic pathogens which can cause public health disease. Owing to their antibiotic-resistance, developing vaccines against these pathogens is urgently required. Herein, we describe the first synthesis of the common O-antigen (trisaccharide to nonasaccharide) of Proteus mirabilis OE and Proteus vulgaris TG 103. Two challenging 1,2-cis-glycosidic bonds were successfully constructed by use of conformation-restrained donors under bifunctional organothiourea catalysis or gold(I) catalysis. A primary immunological evaluation was carried out and the results revealed that the synthetic common O-antigens both hexasaccharide and nonasaccharide can strongly bind with the IgG antibodies in the sera. More details are discussed in the article by Zhang et al. on page 535—543.