Chinese Journal of Chemistry最新文献

Despite recent breakthroughs in organic solar cell (OSC) efficiency, the trade-off between broadening spectral response and minimizing non-radiative energy loss remains a critical bottleneck. While ternary strategies and sequential deposition (SqP) each offer unique benefits, their single-dimensional optimization often fails to balance efficient photon harvesting with ideal vertical phase separation. Herein, we report a multi-dimensional synergistic regulation strategy by incorporating polymer acceptor PYF-T-o into the SqP-processed PM6/eC9 system, where PYF-T-o establishes a cascade energy-level alignment and forms an alloy-like acceptor phase with eC9. This unique microstructure broadens spectral absorption, lowers the donor/acceptor surface energy difference, accelerates crystallization kinetics (reducing nucleation time by 60 ms), and refines phase separation. Consequently, the ternary devices exhibit balanced carrier mobilities, ultrafast charge extraction (0.197 μs), and prolonged carrier lifetime (4.54 μs), effectively suppressing trap-assisted recombination. The energetic disorder is reduced to 23.43 meV, minimizing non-radiative voltage loss from 0.218 eV to 0.205 eV. By utilizing a 2PACz self-assembled monolayer, the optimized device achieves a high power conversion efficiency of 20.23% and demonstrates enhanced photostability with the T₈₀ lifetime extended from 117 h to 260 h. This work establishes a robust paradigm for synchronously reducing energy loss and enhancing device performance via multi-dimensional synergistic regulation.

Metalated covalent organic frameworks (COFs) with two- or three-dimensional (2D/3D) topologies have been extensively studied for various applications. In contrast, their one-dimensional (1D) analogues remain largely unexplored, especially for the electrocatalytic CO₂ reduction reaction (CO₂RR). Herein, we report the design and synthesis of a novel 1D metalated COF, denoted as Por-PBA, constructed via the condensation of 4,4’-(1,10-phenanthroline-2,9-diyl)dibenzaldehyde (PBA) and 5,10,15,20-tetrakis(4-aminophenyl)porphyrin (Por). Upon incorporation of Co ions into Por units, the monometallic CoPor-PBA exhibits enhanced electrocatalytic CO₂RR performance compared to Por-PBA. Interestingly, by programmatical installation of the secondary Fe ions into the PBA moieties, the optimized bimetallic CoPor-Fe_0.22PBA shows significantly enhanced CO₂RR performance relative to the monometallic CoPor-PBA. Particularly, CoPor-Fe_0.22PBA achieves a Faradaic efficiency for CO (FE_CO) of 100% at both –0.7 and –0.8 V vs. reversible hydrogen electrode (RHE), with corresponding partial CO current densities of −3.7 and −6.4 mA·cm⁻², respectively. Mechanistic studies further confirmed the formation of key *COOH and *CO intermediates during the CO₂RR process on CoPor-Fe_0.22PBA. This work highlights the promise of 1D metalated COFs as efficient platforms for CO₂ conversion and underscores the importance of metal-site engineering in developing high-performance COF-based catalysts.

The copolymerization of ethylene with functionalized comonomers under industrially relevant high-temperature conditions remains a great challenge in polyolefin catalysis. Herein, we report a series of arylsilane-bridged dinuclear half-titanocene catalysts designed to enhance thermal stability and comonomer incorporation capability. In ethylene/1-octene copolymerization at 125 °C, the dinuclear catalysts exhibited high activities and achieved 1-octene incorporations exceeding 20 mol%. By tuning reaction conditions, copolymers with molecular weights ranging from 33,000 to 191,000 and incorporations from 8.2 to 25.2 mol% were obtained, matching the metrics of commercial POE grades. More importantly, these catalysts demonstrated remarkable tolerance toward polar OH-functionalized α-olefins, with the dinuclear catalysts showing 2–4 fold higher activities than the mononuclear analogue. The catalysts also enabled efficient copolymerization of ethylene with a carbazole-containing α-olefin, achieving high activities (up to 2.11 × 10⁷ g·mol_Ti^–1·h^–1), high molecular weights (>580,000), and tunable carbazole incorporations (2.7–6.0 mol%). The carbazole-functionalized polyethylenes exhibited unique fluorescence properties, tunable surface wettability, and significantly enhanced ductility. The dinuclear catalyst effect does not follow a universal rule, but is strongly correlated with the specific copolymerization reaction. This work demonstrates that dinuclear half-titanocenes represent a versatile catalyst platform for high-temperature synthesis of functional polyolefin materials with tailored properties.

Phase and defect engineering of molybdenum disulfide provides an effective strategy for regulating oxidant activation in heterogeneous advanced oxidation. Herein, a sulfur-vacancy-rich 1T/2H-MoS₂ heterophase catalyst was developed for peroxymonosulfate (PMS) activation and fluoroquinolone degradation. Compared with 1T-MoS₂ and 2H-MoS₂, the 1T/2H-MoS₂/PMS system exhibited higher activity, better matrix tolerance, and improved regenerability after ethanol washing. Spectroscopic and quenching analyses revealed that PMS activation proceeds mainly through a non-radical pathway dominated by singlet oxygen, with a minor contribution from high-valent molybdenum–oxo species. In situ Raman, EPR, LC-MS, and frontier-orbital analysis further suggested a selective degradation route of ofloxacin, initiated by side-chain oxidation, followed by deeper transformation of the quinolone core. XANES/EXAFS/XPS and DFT calculations showed that the 1T/2H phase boundary and sulfur vacancies cooperatively regulate the local coordination and electronic structure of Mo sites, enabling balanced PMS polarization at interfacial sites while allowing stronger activation at defective motifs. OCTP (organic carbon transfer process) and CRE (catalyst regeneration extent) were further introduced to quantify surface carbon accumulation and catalyst regeneration. This work clarifies how heterophase and vacancy engineering govern selective PMS activation and catalyst durability.

3-Hydroxyindanone represents one of the most valuable and privileged cyclic scaffolds in synthetic and medicinal chemistry, which widely exists in a variety of biologically active natural products and pharmaceutical lead molecules. Benefiting from its reactive hydroxyl and carbonyl functional groups, the 3-hydroxyindanone skeleton also serves as a highly versatile synthetic building block for the modular construction of structurally complex fused and polycyclic ring systems, providing abundant opportunities for molecular diversification and drug molecular modification. Meanwhile, the introduction of fluorinated quaternary stereogenic centers has become a mature and powerful strategy in modern drug discovery. Fluorinated chiral architectures with quaternary C–F stereocenters can effectively optimize the lipophilicity, metabolic stability, and binding affinity of bioactive molecules, endowing them with unique and untapped pharmacological potential compared with their non-fluorinated counterparts. Despite the tremendous advances in the synthetic chemistry of indanone derivatives and fluorinated chiral compounds, the catalytic asymmetric construction of enantiopure 3-hydroxyindanones bearing quaternary C–F stereogenic centers remains a long-standing and unaddressed challenge. The lack of reliable catalytic strategies severely restricts the further development and biological evaluation of such fluorinated chiral 3-hydroxyindanones. To address this synthetic problem and continue our research interest in asymmetric catalysis and fluorine-containing chiral heterocycle synthesis, we herein disclose the first example of catalytic asymmetric allylation for the desymmetrization of 2-fluoro-1,3-indanediones, enabling the facile and efficient construction of chiral 3-hydroxyindanones bearing quaternary C–F stereogenic centers. This newly developed yttrium(III)-based catalytic system exhibits excellent synthetic performance and stereocontrol ability. A broad range of functionalized 2-fluoro-1,3-indanedione substrates are well tolerated under mild reaction conditions, affording the target enantioenriched fluorinated 3-hydroxyindanone products in high yields, excellent enantioselectivities, and exclusive diastereoselectivity (>20 : 1 dr). Notably, this desymmetrization strategy not only provides a straightforward and unprecedented approach to forge challenging fluorinated quaternary stereocenters embedded in indanone skeletons but also offers a practical platform for the synthesis of novel fluorinated chiral drug candidates. We believe this work will enrich the synthetic methodology of fluorinated chiral cyclic compounds and provide new insights for the design and synthesis of fluorine-modified bioactive molecules.

For the first time, polyhedral oligomeric silsesquioxane (POSS) has been used to prepare an octatopic component to co-assemble with cucurbit[8]uril (CB[8]) at room temperature to afford a three-dimensional POSS-based supramolecular organic framework pSOF. Dynamic light scattering experiment reveals that the new highly water-soluble SOF has concentration-dependent nano-scaled sizes, while solution- and solid-phase synchrotron radiation small-angle X-ray scattering experiments indicate that the SOF possesses a mesoporosity with an average size of 2.9 nm and a quite large size distribution. Mice model reveals that pSOF adsorbs photofrin and significantly alleviates its post-treatment phototoxicity, the largest limitation of photofrin as clinically used photodynamic therapeutic agent, but does not impose a negative effect on its photodynamic therapeutic efficacy. The maximum tolerated dose of pSOF for mice is determined to be 170 mg/kg, which is conspicuously higher than the highest value (120 mg/kg) reported for diamondoid-styled SOFs and endows it with the highest therapeutic index.

Electrocatalytic nitrate (NO₃^–) reduction to ammonia (NO₃RR) attracts attention for its mild conditions and ability to convert NO₃^– pollutants into valuable ammonia, yet achieving high yield and long-term stability at low overpotentials remains a major challenge. Here, a homemade carbon paper (HCP) catalyst support with high specific surface area, excellent conductivity, and robust structural stability was constructed from carbon nanotubes (CNTs). Leveraging the uniform surface properties and high surface energy of carbon nanotubes, active CuNi metals self-assemble to form a uniform, dense coating structure with a shell thickness of approximately 3 nm. This structure maximizes active-site exposure and facilitates rapid, spatially coupled tandem reactions during NO₃RR within the same interfacial region, thereby boosting overall catalytic performance, while the intrinsically high surface energy of CNTs thermodynamically suppresses Ostwald ripening of the metal components, conferring excellent long-term catalytic stability. Meanwhile, efficient electrocatalytic NO₃RR at low potentials was achieved by tuning NO₃^– adsorption via Cu and promoting the hydrogenation process through Ni. As a result, the CuNi/HCP catalyst delivered an NH₃ production rate of 16.73 mg·h^–1·cm^–2 at –0.08 V vs. RHE (~90% FE), increasing to 27.15 mg·h^–1·cm^–2 and 96.85% FE at –0.28 V, with stable operation over 456 h.

A useful protocol was reported for preparing trifluoromethylated (hetero)arenes from (hetero)aryl boronic acids or their derivatives: using the easily available organocopper(III) complex, ⁿBu₄N⁺[Cu(CF₃)₄]⁻, in the absence of any additives and under an air atmosphere. Preliminary mechanistic studies indicated that the boron substrate acted as a Lewis acid, abstracting one fluoride from the trifluoromethyl group of ⁿBu₄N⁺[Cu^III(CF₃)₄]⁻, thereby initiating an activation process that produced a neutral Cu(III) intermediate, [(L_n)Cu^III(CF₃)₃] (L_n = solvent or none). Rapid transmetallation with the in situ generated [ArB(OH)₂(F)]⁻ and subsequent reductive elimination yielded the trifluoromethylated arenes. Detailed examination of the reaction's scope revealed compatibility with a broad range of functional groups, including those with acidic protons and C=C bond. Applications of this protocol for trifluoromethylation onto several drug molecules were demonstrated.

1,5-Enenitriles are versatile substrates in cascade radical addition and cyclization reactions for the construction of heterocyclic frameworks bearing new functional groups. However, the reaction process usually generates cyclic iminyl intermediates that could undergo hydrolysis to form ketones, resulting in the loss of the nitrogen atom with low atom economy. The direct capture of iminyl radicals by another radical species to afford nitrogen-retaining products remains a significant challenge which has not been well explored. In this work, we report a fac-Ir(ppy)₃-catalyzed atom transfer radical cyclization of 1,5-enenitriles with thiosulfonates for the synthesis of γ-lactams bearing sulfonyl and N-sulfenyliminyl groups. It is the first application of using thiosulfonates as dual-functional reagents for simultaneous formation of C–S and N–S bonds through a photoinduced cascade radical reaction process. The reactions of 1,5-enenitriles and thiosulfonates were conducted in dioxane under mild conditions using Cs₂CO₃ as a base to form targeted products in moderate to good yields. The photoinduced reaction process first generates sulfonyl and thiyl radicals from thiosulfonates, followed by the addition of sulfonyl radicals to enenitriles, 5-exo-dig cyclization for the formation of iminyl radicals, and finally trapping of the iminyl radicals by thiyl radicals to form difunctionalized γ-lactams. This protocol features a photoinduced reaction process under oxidant-free conditions, having a broad substrate scope and easy scalability, 100% atom economy, and representing a sustainable alternative to the conventional methods in making functionalized imines. Mechanistic studies suggest it has an energy transfer (EnT) pathway for thiosulfonate activation to generate initial radicals, while a base is used in neutralizing acidic byproducts for a better conversion. The effort to extend the reaction scope for selenosulfonates was not successful due to the formation of unstable N-selanylimines that could be readily hydrolyzed to pyrrolidine-2,4-diones. Overall, this work introduces a new synthetic utility of thiosulfonates in atom transfer radical cyclization with 1,5-enenitriles for the generation of iminyl radicals as key intermediates, which are captured by thiyl radicals to form N-sulfenylimines.