4f/5d Hybridization Induced Single-Electron Delocalization in an Azide-Bridged Dicerium Complex.

Dilanthanide complexes with one-electron delocalization are important targets for understanding the specific 4f/5d-bonding feature in lanthanide chemistry. Here, we report an isolable azide-bridged dicerium complex 3 [{(TrapenTMS)Ce}2(µ-N3)]• [Trapen = tris (2-aminobenzyl)amine; TMS = SiMe3], which is synthesized by the reaction of tripodal ligand-supported (TrapenTMS)CeIVCl complex 2 with NaN3. The structure and bonding nature of 3 are fully characterized by X-ray crystal diffraction analysis, electron paramagnetic resonance (EPR), magnetic measurement, cyclic voltammetry, X-ray absorption spectroscopy, and quantum-theoretical studies. Complex 3 presents a trans-bent central Ce-N3-Ce unit with a single electron of two mixed-valent Ce atoms. The unique low-temperature (2 K) anisotropic EPR signals [g = 1.135, 2.003, and 3.034] of 3 indicate that its spin density is distributed on the central Ce-N3-Ce unit with marked electron delocalization. Quantum chemical analyses show strong 4f/5d orbital mixing in the singly occupied molecular orbital of 3, which allows for the unpaired electron to extend throughout the cerium-azide-cerium unit via a multicentered one-electron (Ce-N3-Ce) interaction. This work extends the family of mixed-valent dilanthanide complexes and provides a paradigm for understanding the bonding motif of ligand-bridged dilanthanide complexes.

A novel integrated Urban flood risk assessment approach coupling GeoDetector-Dematel and clustering method.

Urban flood risk assessment plays a crucial role in disaster prevention and mitigation. A scientifically accurate assessment and risk stratification method are of paramount importance for effective flood risk management. This study aims to propose a comprehensive urban flood risk assessment approach by coupling GeoDetector-Dematel and Clustering Method to enhance the accuracy of urban flood risk evaluation. Based on simulation results from hydraulic models and existing literature, the research established a set of urban flood risk assessment indicators comprising 10 metrics across two dimensions: hazard factors and vulnerability factors, among which vulnerability factors include exposure factors, sensitivity factors, and adaptability factors. Subsequently, the research introduced the GeoDetector-Dematel method to determine indicator weights, significantly enhancing the scientific rigor and precision of weight calculation. Finally, the research employed the K-means clustering method to risk zonation, providing a more scientifically rational depiction of the spatial distribution of urban flood risks. This novel comprehensive urban flood risk assessment method was applied in the Fangzhuang area of Beijing. The results demonstrated that this integrated approach effectively enhances the accuracy of urban flood risk assessment. In conclusion, this research offers a new methodology for urban flood risk assessment and contributes to decision-making in disaster prevention and control measures.

Synthesis and characterization of iron clusters with an icosahedral [Fe@Fe12]16+ Core.

Iron-metal clusters are crucial in a variety of critical biological and material systems, including metalloenzymes, catalysts, and magnetic storage devices. However, a synthetic high-nuclear iron cluster has been absent due to the extreme difficulty in stabilizing species with direct iron-iron bonding. In this work, we have synthesized, crystallized, and characterized a (Tp*)4W4S12(Fe@Fe12) cluster (Tp* = tris(3,5-dimethyl-1-pyrazolyl)borate(1-)), which features a rare trideca-nuclear, icosahedral [Fe@Fe12] cluster core with direct multicenter iron-iron bonding between the interstitial iron (Fei) and peripheral irons (Fep), as well as Fep···Fep ferromagnetic coupling. Quantum chemistry studies reveal that the stability of the cluster arises from the 18-electron shell-closing of the [Fe@Fe12]16+ core, assisted by its bonding interactions with the peripheral tridentate [(Tp*)WS3]4- ligands which possess both S→Fe donation and spin-polarized Fe-W σ bonds. The ground-state electron spin is theoretically predicted to be S = 32/2 for the cluster. The existence of low oxidation-state (OS ∼ +1.23) iron in this compound may find interesting applications in magnetic storage, spintronics, redox chemistry, and cluster catalysis.

Natural compound Sanggenon C inhibits porcine reproductive and respiratory syndrome virus replication in piglets.

Porcine reproductive and respiratory syndrome virus is one of the main pathogens threatening the global pig industry, and there is still a lack of effective therapeutic drugs. Sanggenon C is a flavanone Diels-Alder adduct compound extracted from the root bark of the mulberry genus, which has blood pressure-reducing, anti-atherosclerotic, anti-oxidative, and anti-inflammatory effects. In our previous study, Sanggenon C was confirmed to significantly inhibit PRRSV replication in vitro. However, its antiviral potential to inhibit PRRSV infection in vivo has not been evaluated in piglets. Here, the antiviral effect of Sanggenon C was evaluated in PRRSV-challenged piglets based on assessments of rectal temperature, viral load, pathological changes of lung tissue and secretion of inflammatory cytokines. The results showed that Sanggenon C treatment relieved the clinical symptoms, reduced the viral loads in the lungs and bloods, alleviated the pathological damage of lung tissue, decreased the secretion of inflammatory cytokines, and shorten the excretion time of virus from the oral and nasal secretions and feces of piglets after PRRSV infection. The results indicated that Sanggenon C is a promising anti-PRRSV drug, which provides a new strategy for the prevention and control of PRRS in clinical practice.