Applied Organometallic Chemistry最新文献

The utilization of CO₂ as a sustainable feedstock for synthesizing high-value cyclic carbonates via cycloaddition with epoxides is a promising route for carbon resource utilization. However, challenges remain in developing efficient and eco-friendly catalysts under mild conditions. Herein, we report a novel heterogeneous catalyst (HCPs-La) fabricated by immobilizing LaCl₃ in lignin-based hypercrosslinked polymers (HCPs), which were prepared by FeCl₃-catalyzed Friedel–Crafts alkylation reaction. Characterization (FT-IR, N₂ sorption, XRD, TGA, XPS, SEM, TEM, etc.) confirmed the amorphous porous structure, uniform elemental distribution, and thermal stability of HCPs-La. The hierarchical porous structure of HCPs-La, enriched with hydrogen bond donors (–OH, –COOH) and Lewis acid sites (La³⁺), synergistically enhanced CO₂ activation and epoxide ring-opening. Under mild conditions (80°C, 1-MPa CO₂, 20 h), HCPs-La(1) achieved a remarkable yield of 99% for cyclic carbonate. The catalyst exhibited broad substrate adaptability, maintaining high efficiency for diverse epoxides, and demonstrated exceptional recyclability over six cycles without significant activity loss. This work pioneers a lignin-driven catalytic paradigm, where renewable biomass waste is transformed into a high-performance catalyst for CO₂-to-carbonate valorization, aligning with circular economy principles.

This work is focused on the photocatalytic chemodivergent oxidation of indoles by Re(I)dipyrrinato complex. Due to strong absorption in the visible region and high singlet oxygen quantum yields, the Re(I)dipyrrinato complexes can act as highly efficient photocatalysts. A chemodivergent photooxidation of indoles was demonstrated under an oxygen atmosphere featuring low catalyst loading (0.25 mol%) and short reaction time with blue LEDs. A variety of substrates viz., 3-methyl indoles, 2,3-dimethylindoles, N-protected indoles, and 2-methylindoles were utilized to produce N-(2-acetylphenyl)formamide, N-(2-acetylphenyl)acetamide, N-(2-formylphenyl)acetamide, and 2,2-disubstituted indoline-3-ones, respectively, in good to high yields. Mechanistic investigations revealed that the Re(I)dipyrrinato complex in the excited state is involved via photoinduced electron transfer (PET) and energy transfer (EnT) in these reactions. The method is notable for its mild conditions, operational simplicity, and wide scope, suggesting the potential application of Re(I)dipyrrinato complex as an advantageous photocatalyst.

Developing porous-structured organic semiconductor photocatalysts with high charge transfer efficiency is crucial for solar energy utilization, yet remains challenging in pollutant remediation. Herein, an S-scheme C-ZnO/B-g-C₃N₄ photocatalyst with oxygen vacancies was fabricated through modified biomass-derived C doping for methylene blue (MB) degradation. The optimized catalyst achieved 97.8% degradation efficiency within 70 min under visible light. UV-DRS analysis revealed that C doping narrowed the bandgap and enhanced visible-light absorption. XPS results confirmed the S-scheme charge transfer pathway in C-ZnO/B-g-C₃N₄. The synergistic effects of C doping and oxygen vacancies significantly improved charge separation and facilitated S-scheme heterojunction formation. The catalyst exhibited superior photocatalytic performance in alkaline conditions and maintained excellent recyclability. Radical trapping experiments identified the primary reactive species as h⁺ > ·O₂⁻ > ·OH in descending order of contribution. This work provides a promising strategy for solar-driven pollutant remediation by combining biomass-derived carbon modification with S-scheme heterojunction engineering.

The global demand for sustainable and cleaner energy sources has driven more research on advanced desulfurization technologies from fossil fuels, in which oxidative deep desulfurization has become a hotspot. In this paper, the nucleation-controlled method was used to realize the uniform growth of porous amino metal–organic framework (MOF) on green-friendly cotton fibers (CF), and the pore structure and amino functional groups on MOF were beneficial to firmly anchor of P-Mo-W polyoxometalate (POM) active species. Thus, a kind of new supported P-Mo-W POM composite catalyst (POM@MIL-101@CF) has been obtained and exhibited excellent oxidative desulfurization performance for fuels. Under the optimal reaction conditions: T = 60°C, O/S = 7, two pieces of catalyst, the ODS efficiency of 0.5-POM@MIL-101@CF for DBT could reach 99.57%, with slight changes after more than 5 reuse times. Meanwhile, EPR experiments proved that ·O₂⁻ and ·OH radicals were both the main reactive substances, which promoted the remarkable catalytic desulfurization performance of POM@MIL-101@CF. Therefore, this kind of supported POM catalyst is simple to prepare and green-friendly in raw materials, as well as the strong binding between POM and CF with the bridging effects of MIL-101 makes it better adapt to the needs of actual industrial production and has a broad application prospect in practical desulfurization applications.

An efficient method has been developed for preparing heterogeneous palladium catalysts embedded within cellulose spheres, which involves either direct droplet deposition or utilization of an electrospinning technique. The metallic palladium nanoparticles, with an average diameter of 6.39 ± 4.71 nm, were uniformly incorporated into the cellulose spherical matrix. The direct droplet deposition method yielded cellulose spheres with an average diameter of approximately 2.0 mm, whereas those prepared using the electrospinning technique exhibited an average diameter of about 1.0 mm. Intriguingly, the prepared cellulose spheres demonstrated excellent catalytic performance in Suzuki cross-coupling reactions. This phenomenon could be attributed to the predominant distribution of the active Pd⁰ nanoparticles in the outer layer of the cellulose spheres. Significantly, the embedment of active Pd⁰ species greatly enhanced their reusability, as they retained high catalytic activity even after more than 10 cycles. In conclusion, this study presents a straightforward and efficient method for preparing highly active cellulose spheres–supported palladium catalysts, thereby expanding the potential applications of cellulose-based biopolymeric materials.

This study investigated the catalytic potential of novel binuclear copper complexes with halogen-based ligands (Com-X, X = F, Cl, Br, I) in copper(I)-catalyzed azide–alkyne cycloaddition (CuAAC) reactions. All calculations were performed via the MN12-L functional, where the Def2-SVP basis set was employed for all atoms, whereas the copper centers were treated with the Def2-TZVP basis set. The results highlight the thermodynamic stability and electronic properties of these complexes, alongside their noncovalent interactions and reduced density gradient (RDG) analyses. Importantly, the relationship between electronic descriptors (hardness, softness, electrophilicity, and charge transfer capacity) and catalytic activity was explicitly established, showing that the greater softness and charge transfer ability of Com-Br correlate with its lower activation barrier. Among the tested systems, Com-Br demonstrated the most favorable balance of electronic and steric effects, resulting in the lowest Gibbs free energy barrier for the key transition state. The solvent effects further revealed significant variations in the energy profiles, underscoring the influence of the reaction medium. The insights provided herein lay a robust theoretical foundation for understanding the structure–activity relationships in multinuclear copper catalysts, and they offer promising directions for the design and experimental validation of efficient, sustainable CuAAC systems.

The mechanisms for the cyanomethylation of alkenes with acetonitrile were investigated using the M06-L-D3/ma-def2-SVP method (“ma-def2-SVP” indicates that diffuse functions have been added to the def2-SVP basis set). The solvation model based on density (SMD), which is based on solute electron density, was employed to simulate the solvent effect. Computational results reveal that tert-butyl peroxybenzoate (TBPB) acts as a radical initiator, undergoing homolysis to generate t-BuO• and PhCOO• radicals. Additionally, CuX₂ (X = OTf) and NiCl₂(DME) serve as effective catalysts to accelerate this process. The addition reactions between t-BuO• (or PhCOO•) radical and 1,1-diphenylethylene exhibit lower energy barriers, leading to complete C (sp³)-H activation of acetonitrile unsuccessful. C (sp³)-H activation can be completed by CuX₂(X = OTf), forming •CH₂-CN-CuX radical. These radicals and reaction intermediates undergo SN2 reactions to regenerate t-BuO• and PhCOO• radicals. Meanwhile, the selective addition reactions between •CH₂-CN-CuX radical and 1,1-diphenylethylene suggest that C3 atom is the first choice and IRI (interaction region indicator) analysis reveals that vdW (van der Waals) interactions play an important role in the choice for the reactive site; finally, the product intermediate can be generated in large amounts, which could have some paths to yield the final product 4,4-diphenylbut-3-enenitrile (P). Yet, the t-BuO• radical, PhCOO^• radical, CuX₂(X = OTf), and NiCl₂(DME) could be used to finish the reactions. The Gibbs free energy surfaces show that the path with the participation of PhCOO• radicals is optimal. The mechanisms of the byproduct have also been explored. Both these calculations agree with the experimental results. The IRI analysis reveals that the weak interaction can help to reduce the energy barriers.

This study presents a novel ternary heterostructured electrochemical sensor (MOF (Fe)@Fe₃S₄/CNF) by integrating Fe-MOFs, Fe₃S₄, and carbon nanofibers (CNF) for ultrasensitive acetaminophen (APAP) detection. Fe₃S₄ was anchored in situ on Fe-MOFs via ultrasound-assisted hydrothermal vulcanization, coupled with 3D CNF networks. Characterization (XRD, FT-IR, SEM, XPS, and BET) confirmed Fe₃S₄ enhances the MOF electronic configuration via interfacial charge redistribution, while CNF prevents aggregation and boosts conductivity. The optimized sensor shows a wide linear range (0.02–350 μM, R² = 0.9993), ultralow LOD (9.583 nM), > 94% interference resistance (UA, DA), and high recovery (97.33%–104.4%). A triaxial synergy mechanism is proposed: (1) MOF mesopores enable size-selective APAP diffusion, (2) Fe²⁺/Fe³⁺ redox pairs drive catalytic activation via Jahn-Teller effects, and (3) CNF ensures efficient charge transfer. This “pore-activity-conductivity” strategy advances MOF-based sensors through structural precision and interfacial nanoscale engineering for next-gen electrochemical platforms.

A fluorescence (FL) molecular probe based on a naphthalene macrocycle, anchored to two porphyrin subunits (Zn2p), selective for L-tryptophan (L-Trp) has been synthesized. Single-crystal X-ray diffraction, FT-IR, ¹H, ¹³C NMR, and microelemental analyses were applied to characterize Zn2p. The FL spectroscopy represented Zn2p as a sensitive (LOD = 5 × 10⁻⁷ M) and highly selective sensor toward L-Trp in DMF among other selected amino acids. The L-Trp recognition mechanism was studied by ¹H NMR, representing a downfield shift for the proton signals of the OCH₂CH₂O moiety on Zn2p in the presence of L-Trp in CDCl₃ solution. Applying the supramolecular chemical analysis method, the K₁₁ value was calculated as 2.7496 (± 2.1963) × 10⁴ M⁻¹, covering the least computed error. Computational studies were carried out by employing density functional theory (DFT calculations, which were performed in the gas phase using the B3LYP-D3/def2-TZVP basis set in the ORCA 4.1.0 quantum chemistry program, supporting the ¹H NMR result on the involvement of the ethereal oxygen in the supramolecular interaction with L-Trp.

In this study, zeolitic imidazolate frameworks-8 (ZIF-8) was loaded separately with ciprofloxacin (CIP@ZIF-8) and curcumin (CUR@ZIF-8), creating a promising drug delivery system. Various techniques, such as SEM, FTIR, XRD, UV–vis spectroscopy, particle size, and zeta potential measurements, were used to characterize the physicochemical properties of the above two nanocomposites. Their sonodynamic activities were assessed by taking the damage degree of human serum albumin (HSA), which is the most abundant protein in plasma and has multiple important biological functions. Generally, the stronger the sonodynamic activity of the material, the greater the injury to HSA, and the more the fluorescence intensity of HSA decreases. The results confirmed that ZIF-8 could enhance not only the sonodynamic activity of CIP and CUR but also the auxo-action could be heightened to varying degrees with increasing drug concentration, extending ultrasound (US) time, and strengthening US power. Moreover, mechanism experiments found that US combined with ZIF-8 nanocomposites could produce more reactive oxygen species than that of the non-US group. Its production was positively correlated with drug concentration, US time, and US power. To sum up, this study made a significant exploration of ZIF-8 as a good sonosensitizer accelerator and provided a new research idea for the development of more efficient sonosensitizers.