De-Xian Wang’s research while affiliated with Chinese Academy of Sciences and other places

The efficient binding of dicarboxylates represents an important yet challenging issue in supramolecular chemistry. In this study, we designed functional ultracycles as hosts to accommodate large organic dicarboxylate anions. These ultracycles were synthesized via a one-pot strategy starting from macrocyclic precursors. Host–dicarboxylate binding was investigated using ¹ H NMR titrations, revealing that B4aH exhibits strong binding affinities toward a series of dicarboxylates, with association constants reaching up to 6896 M ⁻¹ . The selectivity for heptanedioate ( C7 ²⁻ ) was attributed to cooperative hydrogen bonding, anion–π interactions, and a size-matching effect, as supported by DFT optimizations.

Anion-carbonyl interaction is a newly developed non-covalent bond, and its application as a driving force in supramolecular chemistry deserves exploration. Herein, a series of barbiturate-containing macrocycles were synthesized using macrocycle-to-macrocycle transformation or one-pot macrocyclization. Various structural conformations arising from the interplay of non-aromatic barbiturate and benzene rings through N–C rotations in solution were revealed. The macrocycles featuring carbonyl donors and acceptors resulted in unique self-assembly structures and host-guest complexes in the crystalline state. The [3+3] macrocycle 7a was applied as a host molecule to investigate the complexation with anions by 13C nuclear magnetic resonance (NMR) titrations, which showed selective binding towards malonate with an association constant of Ka(1:1) = 13.2 ± 1.57 M−1. Multiple anion-carbonyl interactions between 7a and malonate were revealed by density functional theory (DFT) optimization of the complex.

C 3-symmetric aromatic triimides (ATIs) represent an interesting class of electron-deficient molecular backbones, characterized by π-conjugated aromatic cores symmetrically substituted with three imide groups. Their unique structural and electronic features, combined with exceptional stability and straightforward N-functionalization at three imide sites, make ATIs promising as versatile building blocks for applications in supramolecular chemistry and materials science. Despite their promising attributes, research on ATIs remains underexplored compared to the extensively studied aromatic imides and diimides, largely due to the synthetic challenges involved in constructing three imide groups on the aromatic frameworks. In recent years, advances in synthetic protocols have significantly propelled ATI-related chemistry, expanding their applications in the realm of functional materials. This review compiles advancements in the synthesis, structural and physicochemical properties, and applications of ATIs in supramolecular chemistry and advanced materials. We anticipate that this review will not only draw greater attention to ATIs but also serve as a valuable guide for future research into these molecular building blocks.

Biocatalysis provides an eco-friendly and efficient method for the synthesis of fine chemicals, pharmaceuticals, and biofuels. However, the catalytic performance of enzymes is greatly reduced when they react under non-optimal...

Biocatalysis is an attractive approach for the synthesis of chiral pharmaceuticals and fine chemicals, but assessing and/or improving the enantioselectivity of biocatalyst towards target substrates is often time and resource intensive. Although machine learning has been used to reveal the underlying relationship between protein sequences and biocatalytic enantioselectivity, the establishment of substrate fitness space is usually disregarded by chemists and is still a challenge. Using 240 datasets collected in our previous works, we adopt chemistry and geometry descriptors and build random forest classification models for predicting the enantioselectivity of amidase towards new substrates. We further propose a heuristic strategy based on these models, by which the rational protein engineering can be efficiently performed to synthesize chiral compounds with higher ee values, and the optimized variant results in a 53-fold higher E-value comparing to the wild-type amidase. This data-driven methodology is expected to broaden the application of machine learning in biocatalysis research.

It has long been an aspirational goal to create artificial channel structures that replicate the feat achieved by ion channel proteins. Biological ion channels occasionally demonstrate multiple conductance states (known as subconductance), remaining a challenging property to achieve in artificial channel molecules. We report a funnel‐shaped single‐molecule channel constructed by an electron‐deficient macrocycle and two electron‐deficient aromatic imide arms. Planar lipid bilayer measurements reveal distinct current recordings, including a closed state, two conducting states, and spontaneous transitions between the three states, resembling the events seen in biological ion channels. The transitions result from conformational changes induced by chloride transport in the channel molecule. Both opening states show a non‐linear and rectifying I–V relationship, indicating voltage‐dependent transport due to the asymmetrical channel structure. This work could enhance our understanding of ion permeation and channel opening mechanism.

It has long been an aspirational goal to create artificial channel structures that replicate the feat achieved by ion channel proteins. Biological ion channels occasionally demonstrate multiple conductance states (known as subconductance), remaining a challenging property to achieve in artificial channel molecules. We report a funnel‐shaped single‐molecule channel constructed by an electron‐deficient macrocycle and two electron‐deficient aromatic imide arms. Planar lipid bilayer measurements reveal distinct current recordings, including a closed state, two conducting states, and spontaneous transitions between the three states, resembling the events seen in biological ion channels. The transitions result from conformational changes induced by chloride transport in the channel molecule. Both opening states show a non‐linear and rectifying I–V relationship, indicating voltage‐dependent transport due to the asymmetrical channel structure. This work could enhance our understanding of ion permeation and channel opening mechanism.