Science China Chemistry最新文献

Tumor-targeted radiopharmaceuticals have become an attractive modality for tumor diagnosis and treatment in clinics. However, their wide clinical applications are seriously impeded by poor tumor targeting, rapid systemic clearance, and short tumor retention. Therefore, developing advanced radiopharmaceuticals with great tumor specificity and prolonged retention time is highly desirable for efficient tumor treatment. Herein, we report a tumor-targeted covalently anchoring strategy that selectively crosslinks the radiopharmaceuticals to intratumoral macromolecules for prolonged tumor theranostics. A covalent multi-targeted radiopharmaceutical (CMTR) d-IR-2(¹²⁵IRGD) that includes a sulfenic acid-reactive 1,3-cyclohexanedione group was developed. We demonstrated this probe could specifically accumulate at the tumor site and bind to the sulfenated proteins that are overexpressed within tumors, which greatly prevents the efflux of probes in tumor tissues while having faster clearance in healthy tissues resulting in 12 h longer tumor retention than conventional probes for sensitive NIR and SPECT/CT detection of tumors in vivo. More notably, the ¹³¹I-labeled probe could significantly suppress the growth of lung tumor A549. We thus envision that this work may offer a promising approach to developing effective radiopharmaceuticals for precise diagnosis and treatment of various tumors.

The selective construction of sophisticated supramolecular topologies has always attracted the remarkable attention of researchers. Thus, various molecular knots and catenanes have recently been reported and were obtained either accidentally or by following a previously planned synthetic strategy. Herein, we introduce a series of supramolecular topologies including double trefoil knot (1), trefoil knot (2) and [2]catenanes (4, 5), which were prepared via an elaborated self-assembly strategy by using half-sandwich units based on a flexible pyridyl linker L1. The formation of all the structures has been confirmed by single crystal X-ray diffraction analysis and NMR spectroscopy, and ESI-MS. Remarkably, the central potassium ion of 1 coordinates six oxygen atoms belonging to six amide groups from two trefoil segments. The double trefoil knot 1 and [2]catenanes 4, 5 are stabilized by parallel-displaced π⋯π stacking interactions (of interlayer distance 3.34–3.82 Å) between the pyridyl fraction and phenyl moieties of three ligands L1, and by edge-to-face-type CH⋯π interactions (2.64–2.83 Å) between BiBzIm conjugated planes and phenyl hydrocarbon bond. Interestingly, the addition/removal of potassium ions resulted in topological transformation between the double trefoil knot 1 and the trefoil knot 2. In addition, the addition of DMF-d₇ to a methanolic solution of the double trefoil knot 1 induced its structural conversion into the metallamacrocycle 3. NIR photothermal studies of 1, 4, and 5 showed different photothermal responses in solid and solution states. Thus, the photothermal conversion efficiencies of 4, and 5 were within the limit of 16.8%–45.1% based on different power areas, the number and the fashion of π⋯π stacking interactions can directly affect the photothermal conversion efficiency, and EPR experiments confirmed the recorded results.

Gel polymer electrolytes (GPEs) are conceived to be a good way to build safer lithium/sodium metal batteries by substituting traditional liquid electrolytes. However, it is still very difficult for GPEs to simultaneously achieve high room-temperature ionic conductivity, uniform Na⁺ flow, superior interfacial compatibility, and increased mechanical strength. Herein, a composite gel electrolyte (KNT-PTGPE) with high ionic conductivity of 4.06 mS cm⁻¹ is prepared through chemical crosslinking strategy and the introduction of inorganic nanoparticles. The hybrid gel polymer network is formed by in situ cross-linking modified TiO₂ (KNT), three-armed trimethylolpropane trimethacrylate and poly(ethylene glycol) diacrylate. The resulting 3D interpenetrating network facilitates the absorption of liquid electrolytes and improves the mechanical properties of electrolyte. Theoretical calculation and in situ measurements reveal that the homogeneous TiO₂ fillers with abundant Lewis acid site and polymer network are involved in the solvation process of Na⁺, thus constructing a fast Na⁺ transport channel. Consequently, a stable plating/stripping process lasting over 900 h is achieved due to the uniform distribution of Na⁺ flux and the good mechanical properties of the electrolyte, and the assembled cell exhibits an excellent long-term cycling stability. The approach offers more opportunities to design GPEs for high performance SMBs.

Establishing supply chains for future ammonia energy systems requires the development of efficient materials and processes for ammonia production under mild conditions. Recent researches disclose unique functionalities of binary alkali and alkaline earth metal hydrides in mediating ammonia synthesis. Thanks to the rich compositional and structural properties of the metal-hydrogen system, we herein report that LiBaH₃, as a narrow band gap perovskite hydride, exhibits a strong response to visible light illumination. Specifically, hydridic hydrogen undergoes reductive elimination of producing H₂ and creates an electron-rich surface. Such an environment favors dinitrogen fixation to form N–H bonds. Based on this chemical property, a chemical looping ammonia synthesis process mediated by LiBaH₃ and driven by both photo and thermal energies was proposed and evaluated. This work demonstrates that hydride perovskites are promising candidates for mediating photo-assisted nitrogen fixation reactions.

Metal-organic frameworks (MOFs) based on anion exchange membranes (AEMs) have garnered considerable interest, particularly for their potential to enhance ion conductivity by pre-introducing anions into MOFs. This approach is recognized as straightforward and effective for improving ion conductivity. However, developing high-performance AEMs is limited by the inherent instability and low resistance of MOFs. This study presents a novel 1,3,5-triazine μ₃-bridged neutral Cu(I) framework, designated SXU-120 (where SXU represents Shanxi University). This framework is synthesized using melamine, a widely available industrial product, as the starting material, achieving a high space-time yield exceeding 1.1 kg m⁻³ day⁻¹. The organic ligands and metal ions in SXU-120 are 3-connected, forming a rare eta topology with the point symbol 8³. SXU-120 exhibits exceptional stability, even in a 10 M KOH solution, due to its high density of uncoordinated–NH₂ and carbonyl groups. Furthermore, the framework’s unique one-dimensional channels, characterized by their electronegativity, interact electrostatically with OH⁻ ions, thereby accelerating OH⁻ ion transfer along these channels. Consequently, the OH⁻ conductivity of this material reaches an impressive 0.49 S cm⁻¹ at 90 °C under full humidity for 100 h, representing the highest OH⁻ conductivity reported for MOF-based conductors to date. These properties make SXU-120 a promising candidate for efficient AEM materials in next generation industrial applications.