Applied Organometallic Chemistry最新文献

Photodynamic therapy (PDT) is an effective strategy for eliminating primary tumors, but local hypoxia within tumor tissues significantly limits its efficacy. Additionally, premature leakage of photosensitizers (PS) from nanocarriers not only reduces their targeted accumulation in tumors, but also increases their nonspecific distribution in healthy tissues, which further impairs the efficiency of PDT and enhances systemic phototoxicity. Herein, we have developed a highly efficient and specific nanoplatform for cancer therapy. This platform utilizes polyethylene glycol-modified gold nanoparticles (AuNPs) as carriers, coated with a multifunctional shell that controls the release of the photosensitizer Chlorin e6 (Ce6) and modulates tumor hypoxia. This design overcomes two key limitations of PDT: premature PS leakage and local hypoxia in the tumor microenvironment. By catalyzing the decomposition of endogenous hydrogen peroxide (H₂O₂) within tumors, the platform generates oxygen, thereby alleviating hypoxia and enhancing Ce6’s ability to generate reactive oxygen species (ROS) under near-infrared irradiation. Moreover, the glucose oxidase-like activity of AuNPs induces glucose depletion in tumor cells, promoting disulfidptosis, a form of cell death triggered by disulfide stress. In vitro experiments demonstrate that the nanoplatform selectively induces cancer cell death without affecting normal cells, underscoring its excellent biocompatibility and therapeutic potential. These findings suggest that the combination of controlled Ce6 release, hypoxia alleviation, and glucose depletion significantly enhances the efficacy of PDT, providing a novel cancer treatment strategy with broad applications to address the challenges of hypoxia and premature drug release.

The green synthesis of titanium dioxide nanoparticles (TiO₂ NPs) using Endostemon viscosus (Roth) M. R. Ashby leaf extract, in which the plant metabolites acted as reducing and capping agents. The green synthesized TiO₂ NPs exhibited an anatase crystalline phase with spherical morphology, good colloidal stability (zeta potential −23.1 mV), and particle sizes ranging from 50 to 110 nm. The nanoparticles demonstrated notable biological activities, showing enhanced antibacterial efficacy against Gram-positive bacteria, strong antioxidant potential (DPPH and ABTS assays), significant anti-inflammatory activity, and potent anticancer activity with a low IC₅₀ value (10.38 ± 1.93 μg/mL). These findings highlight the effectiveness of E. viscosus-mediated TiO₂ NPs and their promise as eco-friendly nanomaterials for pharmaceutical and anticancer applications.

Developing efficient dual-target chemosensors for the detection of toxic metal ions and biologically relevant amino acids remains a significant challenge. In this work, an azomethine-linked silane (Compound 3) was designed, synthesized, and thoroughly characterized. Photophysical studies revealed that Compound 3 exhibits excellent sensitivity and selectivity toward Cd(II) ions. Furthermore, the in situ formed Compound 3–Cd(II) complex exhibited selective recognition of arginine (Arg) over other competing amino acids, demonstrating its dual sensing capability. The sensor showed remarkable limits of detection, with 3.8 nM for Cd(II) and 0.4 μM for Arg, enabling detection well below environmental and biological safety thresholds. Practical applicability was validated through water sample analysis, which afforded high percentage recovery values. In addition, Compound 3 displayed significant free-radical scavenging activity, as evaluated by the DPPH assay, highlighting its potential relevance in oxidative stress-related biological applications.

To enhance charge carrier separation and migration efficiency during photocatalytic hydrogen evolution, thereby improving overall photocatalytic performance, a Z-Scheme heterojunction of Ti-Ni bimetallic MOF/Ultrathin g-C₃N₄ was prepared via high-temperature annealing method. As a photocatalyst, the composite was applied in the hydrogen evolution. The hydrogen production yield reached 21.42 mmol·g⁻¹ within 6 h upon exposure to simulated sunlight, the average hydrogen evolution was measured as about 3.75 mmol h⁻¹ g⁻¹, which was 2.63-fold enhancement over that of PCN. The hydrogen generation rate of the heterojunction maintained well within a 4-cycle test, the average H₂ evolution was more than 3.60 mmol h⁻¹ g⁻¹. The prepared heterojunction exhibits high catalytic performance and good stability in the domain of photocatalysis of H₂ generation, which provide a novel alternative for subsequent investigations into solar-driven hydrogen evolution.

A novel Cd-based MOF, {[Cd (bipd)₂(H₂O)₂](NO₃)₂}_n (bipd = 3,5-bis(1-imidazolyl)pyridine), was successfully synthesized, comprehensively characterized. Structural determination demonstrated the Cd (II) centers formed a three-dimensional mesh-type coordination framework with high density of exposed active sites, contributed to exceptional Fenton-like activity, achieving 91.26% degradation of methylene blue within 10 min. Furthermore, it showed significant antibacterial performance against Gram-positive and Gram-negative bacteria, with minimum inhibitory concentration values as low as 8 μg/mL; molecular docking was employed to explore the potential interaction between key enzymes, which serves as a valuable reference for understanding the bacteriostatic mechanism. These findings demonstrated that the synthesized Cd-MOF exhibited dual functionality for wastewater treatment, showing simultaneous efficacy in organic dye degradation and microbial inactivation.

A series of composites C_xPMo₄@MIL-100(Fe) (x = 4, 8, 12, and 16) were synthesized via one-pot solvothermal method, characterized by various techniques, and employed as catalyst for extraction oxidation desulfurization of multicomponent simulated fuel. Among them, C₈PMo₄@MIL-100(Fe) exhibited optimal catalytic activity, achieving 99.8% total desulfurization efficiency within 60 min under the optimal conditions. In addition, the desulfurization efficiency decreased in the sequence DBT > 4-MDBT > 4,6-DMDBT > BT, which was attributed to the interplay between steric hindrance and electron density of the sulfide molecules. Furthermore, C₈PMo₄@MIL-100(Fe) exhibited excellent reusability, maintaining an efficiency of over 92% after six consecutive cycles. These findings emphasize the crucial role of adjusting the interaction between polyoxomolybdenum and metal–organic frameworks to achieve efficient and sustainable fuel desulfurization, and provide a theoretical basis for the rational design of high-performance heterogeneous catalysts.

Given their role as pivotal intermediates for synthesizing bioactive molecules, pharmaceuticals, and high-value chemicals, the development of efficient and sustainable routes to N-alkylamines is of paramount importance. Addressing this, a CoNi@CeO₂-CN composite was precisely engineered via a multistep process involving the self-assembly of a Co/Ni/Zn/Ce-MOF precursor, followed by chemical vapor deposition and pyrolysis. Comprehensive characterization (SEM, XRD, and XPS) verified the successful formation of the desired microstructure and chemical composition. The catalyst exhibited outstanding performance in the hydrogenation-alkylation of nitrobenzene with benzyl alcohol, achieving complete conversion (100%) and an exceptional selectivity (99.6%) for N-benzylbenzylamine, thereby positioning it as a premier candidate for advanced amine synthesis.

In this paper, two cobalt(III) hydrides, [(PMe₃)₃Co(H)(Cl)(SiH₂Ph)] (3) and [(LSi:)₂(PMe₃)Co(H)(Cl)(SiH₂Ph)] (LSi: = {PhC (N^tBu)₂}SiCl) (4), were used as catalysts to compare their catalytic performance on the hydrosilylation of alkenes. The research results indicate that both cobalt(III) complexes 3 and 4 are good catalysts for the hydrosilylation of alkenes, affording Markovnikov products for aryl alkenes and anti-Markovnikov products for alkyl alkenes. It was found that the catalytic activity of phosphine cobalt(III) hydride 3 is higher than that of silylene cobalt(III) hydride 4 for aryl alkenes. On the contrary, the catalytic activity of silylene cobalt hydride 4 is better than that of phosphine cobalt hydride 3 for alkyl alkenes. Different experiments were designed to study the catalytic mechanism for hydrosilylation of alkenes catalyzed by complexes 3 and 4. We found that complex 3 first reacted with Ph₂SiH₂ when it was used as a catalyst. From the stoichiometric reaction between complex 3 with Ph₂SiH₂ we obtained the known complex 5 [(Ph₂ClSi)Co(H)₂(PMe₃)₃]. Further experiment indicates that hydrido cobalt(I) intermediate 5b, [HCo (PMe₃)₃], is an active intermediate in the hydrosilylation of alkenes catalyzed by complex 3. When silylene cobalt(III) hydride 4 was used as a catalyst, complex 4 reacted at first with styrene, and four-coordinated bis (silylene) cobalt(I) chloride Co (LSi:)₂(PMe₃)Cl was proposed as the active intermediate in the hydrosilylation of alkenes. Based on the experimental results, two different possible catalytic mechanisms catalyzed by complexes 3 and 4 were proposed, respectively.