Second near-infrared region (NIR-II) small-molecule fluorophores hold great promise for biomedical imaging because of their well-defined chemical structures, superior metabolic properties, deep tissue penetration, and unprecedented clarity. However, it is impossible to apply conventional synthesis methods for the in-situ generation of NIR-II fluorophores in living organisms because of the need for high temperatures, strong acids or bases, and anhydrous conditions. Herein, we report an innovative strategy to create NIR-II hemicyanine (NIR-II-Hcy) with high conversion efficiency (up to 86%) under mild conditions, using β-chloroacroleins derivatives (Pre-Hcy) and meta-aminothiophenol as precursors without harsh conditions. Interestingly, this method can be extended to live mice, and the acidic microenvironment is conducive to the rapid production of NIR-II-Hcy (k_{pH = 6.0}/k_{pH = 8.0} = 10). Furthermore, by leveraging the formation/cleavage of disulfide bonds and the acidic microenvironment, the in-situ generation of NIR-II-Hcy enables the activation to be controlled by glutathione (GSH) and H⁺, thereby enabling high-contrast and discriminative in vivo tumor imaging, and this work establishes the first paradigm for tumor microenvironment-driven NIR-II fluorogenesis. This is a novel finding that will facilitate simpler and faster synthesis of NIR-II dyes with broad applications in biomedical research and clinical diagnostics.

Reticular chemistry enables the precise design and synthesis of crystalline extended materials, however, its application in hierarchical self-assembly of superstructures remains challenging due to the limited control over weak interactions between synthons, in contrast to the stronger coordination or covalent bonds typically involved. Herein, we introduce an anion-competitive strategy to control the topology and structural diversity of superstructures. Cationic tetrahedral Zr-based metal–organic polyhedra were used as cage-like synthons, which were charge-balanced by Cl^– ions and interconnected via hydrogen bonds to form hierarchical superstructures. Introducing trigonal planar NO₃^– ions to compete with spherical Cl^– ions produced three new superstructures featuring different hydrogen bond-based linkages and distinct topologies (dia, bnn, and xhy), diverging from the previously reported flu topology. Furthermore, the superstructures with dia and bnn topologies exhibit high porosities and record iodine adsorption capacities in solution (4.31 and 4.19 g·g^–1, respectively). This work demonstrates the potential of reticular chemistry for the versatile design and construction of diversified hierarchical superstructures.

Birefringent crystals exhibit significant advantages in the field of polarization state modulation due to their unique optical anisotropy properties. The property optimization between bandgap and birefringence depends on the crystal structure, which is always a key scientific problem in the field of functional crystal materials design. In this work, the fluorination-oriented strategy was applied to the design of crystals with large birefringence and deep ultraviolet (DUV) cutoff edges. By introducing the fluorinated [SiF₆] octahedron, the arrangement orientation of the π-conjugated [C(NH₂)₃] groups was accurately regulated, thereby achieving the design and preparation of a new crystal [C(NH₂)₃]₂SiF₆ with a large bandgap (6.34 eV) and large birefringence (0.16 @546 nm). In addition, [C(NH₂)₃]₂SiF₆ (GSF) can obtain large-sized crystals through a simple water solution evaporation method, and it has unique advantages such as low cost and easy growth. The synergistic mechanism between the core factors of significant birefringence and wide bandgap in [C(NH₂)₃]₂SiF₆ was revealed through experimental characterization and theoretical calculation. This work provides promising candidates with exceptional properties for DUV applications.

The synthesis of fused arenes from non-aromatic precursors is useful but challenging. Herein, the synthesis of widely-used naphthylamines was focused. The three-component reactions of p-quinols, enals and amines were investigated under the dienamine/iminium- based dual organocatalysis. The efficient synthesis of naphthylamines was achieved via a formal [3+3] cyclization of the amines activated p-quinols and enals, with the following Bu₄NOAc/AgNO₃ facilitated dual aromatization. The different reactivity of in-situ generated dienamine and iminium intermediates resulted in the differentiating catalysis, providing an efficient and practical methodology for the synthesis of fused arenes from non-aromatic precursors.

Aluminum-based metal-organic frameworks (Al-MOFs) feature low density, high stability, and non-toxicity, making them highly promising for adsorption-related applications. In this study, we report the construction of a novel nia-type Al-MOF based on 6-connected trinuclear Al₃ clusters, HIAM-341, employing an isophthalate-derived hexatopic linker. It exhibits a robust structure with a BET surface area of 1094 m²·g^–1, with a pore size of 4.7 Å. HIAM-341 demonstrates size-sieving separation of hexane isomers, with adsorption capacities of 164 and 54 mg·g^–1 for n-hexane and 3-methylpentane at 303 K and 1 bar, respectively, while excluding 2,2-dimethylbutane. Multicomponent breakthrough experiments further confirm its separation capability, and the underlying selective molecular exclusion mechanism has been uncovered by DFT calculations. Our research provides new insights into the rational design of robust Al-MOFs with tailored pore structures by employing organic linkers with high coordination density for targeted separations.

The transition metal-free chalcogen trifluoromethylation of alkenes represents a highly efficient transformation for the rapid generation of C(sp³)-rich aliphatic trifluoromethyl compounds. However, a unified methodology to achieve oxy-, thio-, and seleno-trifluoromethylation remains elusive yet highly desirable. In this study, we report a triarylamine-catalyzed three-component vicinal chalcogen-trifluoromethylation of alkenes under blue light irradiation without the need of transition metal catalyst. This reaction is broadly applicable to oxy, thio, and seleno nucleophiles, facilitating modular access to a diverse array of β-trifluoromethyl alcohols, ethers, thioethers, thiocyanates, and selenocyanates with good yields and predictable regioselectivities (61 examples). Additionally, we demonstrate its application in the late-stage modification of natural products and pharmaceutical compounds. Preliminary mechanistic studies suggest that a catalytic electron donor-acceptor (EDA) complex between triarylamine and the Umemoto reagent is key to enabling the radical/polar crossover process.

Developing method for strong Si–F σ bond activation is a very important tool in organosilicon transformation chemistry, only few examples of Si–F bond activation are precedent in the literature. Herein, we developed a new and efficient method to activate strong Si–F bond by transition-metal-free Si–F/Si–H cross coupling reaction catalyzed with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) catalytic system under mild conditions. Various disiloxanes bearing tolerated functional groups were successfully synthesized in moderate to excellent yields from fluorosilanes and hydrosilanes. Moreover, H₂O was found to be the oxygen donor in this catalytic system. Density functional theory calculations were performed to verify the mechanism of DBU promoted Si–F/Si–H cross-coupling reactions.

The development of circularly polarized luminescence (CPL) materials from simple organic molecules is of critical importance for advancing their practical applications, yet it remains hindered by challenges such as low dissymmetry factors (g_lum) and complex synthetic process. Herein, we report a facile one-step [2+2] condensation strategy to access a Schiff-base pyrene dimer featuring 1,6-substituted pyrenes and trans-1,2-diaminocyclohexane units in 77% yield. Taking advantages of face-to-face π-π stacking of pyrene rings in the constrained D₂ symmetric structure, intense excimer CPL was successfully realized with a |g_lum| value of 0.021 and a CPL brightness, B_CPL, value of 154.5 M^-1·cm^-1. The optimized excited state structures reveal that the high |g_lum| value arises from the parallel arrangement of electric and magnetic dipole transition moments. Importantly, the rigid pyrene dimer architecture ensures robust CPL performance invariant under diverse conditions, including changes in temperature, concentration, and solvents, as well as in polymer films.

The chiral phosphoric acid catalyst enables the atroposelective arylation of 5-aminoisoxazoles and quinones by accelerating the kinetics of the enantioselective catalytic reaction, effectively outcompeting and even suppressing the uncatalyzed racemic background reaction. In this strategy, a large panel of axially chiral isoxazole-derived amino alcohols was synthesized with generally high yields and excellent enantioselectivities. The method features mild reaction conditions, broad functional group compatibility and good scalability. X-ray crystallography and thermal racemization experiments revealed the important role of six-membered intramolecular O−H···O hydrogen bonding in stabilizing the configurations, which exhibit markedly different racemization barriers in protic and aprotic solvents. Moreover, preliminary mechanistic studies, including nonlinear effects and control experiments were conducted to elucidate the reaction mechanism and activation mode. This approach not only provides an efficient method for constructing pentatomic isoxazole scaffolds, but also expands the family of axially chiral amino alcohols.

Transition metal-catalyzed functionalization of unsymmetrical internal alkynes remains challenging because of the difficulty in controlling regioselectivity of migratory insertion of alkynes into the C–metal bonds. Moreover, the synthesis of C–N atropisomers has received significantly less attention compared to that of C–C atropisomers and there have been only a few isolated examples reported for the construction of chiral diaxes through C–H functionalization. Herein, we report that cobalt can catalyze the C–H annulations of aminoquinoline amides with directing group-tethered internal alkynes or 1-indolylalkynes for the synthesis of chiral diaxes. A variety of vicinal C–N and C–C chiral diaxes and distal double C–N chiral diaxes were synthesized with excellent regio, diastereo, and enantioselectivity under mild reaction conditions. The ready availability of aminoquinoline amides, alkynes, and Salox ligands and the simplicity and good functional group tolerance of this protocol make it highly attractive.

A palladium catalytic system incorporating novel Fc-JosiPhos ligands enables efficient C–N bond formation with diverse (hetero)aryl halides under low palladium loading (0.1 mol%). We rationally designed novel ferrocenyl phosphine-derived JosiPhos ligands (L1–L3). These ligands incorporate a ferrocenyl group providing greater steric bulk than tert-butyl or cyclohexyl and superior electron donation to cyclohexyl, along with a tunable side chain. They delivered excellent yields in the catalytic coupling of challenging (hetero)aryl chlorides with hydrazine. The scalable synthesis of arylhydrazines (5 mmol scale) and subsequent cyclization to pyrazoles (65%–91% yields) highlights their potential for industrial conversion. Furthermore, the modularity of this strategy supports late-stage pharmaceutical functionalization, exemplified by TRPC inhibitor intermediate.

Fluorogenic probes with "off-on" fluorescence signals have emerged as powerful tools for biosensing and bioimaging of biomolecules in living systems. Conventional single-target probes, however, often suffer from false-positive signals due to non-specific activation in non-target tissues or the diffusion of activated fluorescent products. To address these limitations, dual-targeted fluorogenic probes (DTFPs) have been developed, which simultaneously target two biomarkers to enhance detection specificity and minimize false-positive outcomes. DTFPs are designed to activate or retain fluorescence only when both biomarkers are present within a targeted region, enabling precise in vivo imaging of pathological conditions such as tumors and inflammation. This review highlights recent advances in DTFP development, focusing on their design principles, activation mechanisms, and applications in biosensing and bioimaging. We also discuss current challenges and future directions for DTFP research, aiming to inspire the design of next-generation probes with improved accuracy and specificity. By providing a comprehensive overview of DTFPs, this review seeks to advance their potential for transformative applications in biomedical imaging and diagnostics.