Chemistry - An Asian Journal最新文献

Tetracyanoethene (TCNE)-integrated π-systems exhibit strong donor-acceptor (D-A) interactions and display intriguing optical and electronic properties, making them ideal candidates for electrochromism. However, such studies have never been carried out. Here, we report the synthesis and electrochromic properties of novel 1,1,6,6-tetracyanohexatriene (TCHT)-based chromophores (TS1-3 & TA1-2). These compounds have been developed via double [2+2] cycloaddition-retroelectrocyclization (CA-RE) of various electron-rich alkynes (triphenylaminyl, ferrocenyl, and anisyl) with TCNE. The chromophores exhibit intense intramolecular charge transfer (ICT) resulting in strong colors, low-energy absorption extending into the near-infrared (NIR) region (∼900 nm), narrow band gaps (∼1.90 eV) and low LUMO levels (∼-3.5 eV). Upon applying the reduction potential of ∼-1.0 V, TS1-3 and TA1-2 exhibit reversible electrochromism in solution and the solid state with an associated color switching from dark blue↔purple, yellow↔pink, blue↔yellow and green↔blue, purple↔blue, respectively. The process is rapid with a switching time of 1-2 s and stability over 48 redox cycles. The study also reveals a unique electrochromic color tuning behavior of TS1 upon varying the solvent medium (CH₂Cl₂, THF, and CH₃CN) from blue to purple, and then to yellow. These findings establish TCHT-based chromophores as promising candidates for advanced electrochromic devices.

All-carbon macrocyclic compounds are useful chemical components for drug molecules, nanomaterials, and catalyst supports. The access of macrocyclic compounds is trapped in the absence of efficiency and flexible synthetic approaches besides obtaining from natural products. In this study, the first case of synthetic fused all-carbon cyclododecadiene and cyclohexadecatetraene through the multistep tandem cyclization of an α,3-dehydrotoluene-type reactive intermediate derived from pentadehydro-Diels-Alder (PDDA) reaction with conjugated olefins was reported. This method circumvents the use of specific catalysts, complex operations, and low yields. Density functional theory calculations reveal the formation of biradical intermediates, which play a crucial role in optimal reaction process.

Manganese hexacyanoferrate (MnHCF), also known as Prussian white cathode material, has become a popular choice for sodium-ion batteries due to its high output voltage, low cost, and high theoretical specific capacity. However, MnHCF synthesized via conventional methods exhibits a cubic phase, presenting issues such as CN vacancies, crystalline water, poor conductivity, and complex phase transitions during charge-discharge cycles. These factors lead to low capacity utilization and poor cycle life, limiting its application in sodium-ion batteries. The performance of Prussian white cathode material is closely related to its structure. In this study, MnHCF with monoclinic phase characteristics was synthesized by introducing nitrogen as the reaction atmosphere. After 200 cycles at 5C, its capacity retention rate was 75%, showing more excellent cycle performance and rate performance compared with the cubic phase. Additionally, this work investigates structural changes during moderate discharge cycles. Crucially, in situ EIS and cyclic voltammetry at varying scan rates characterize the evolving kinetic processes throughout charge-discharge cycles. This study presents an effective synthesis strategy, which is helpful for the design and optimization of Prussian blue analog sodium-ion batteries.

Manganese-based photocatalysis has emerged as a sustainable strategy in modern organic synthesis, leveraging manganese's natural abundance, low toxicity, versatile redox behavior, and tunable coordination environments. This review classifies manganese photocatalysts into three main structural categories: (i) dinuclear Mn₂(CO)₁₀, (ii) mononuclear complexes with simple ligands (including manganese salts), and (iii) well-defined complexes supported by elaborate ligand frameworks. The article systematically summarizes their applications in a range of photocatalytic transformations, such as C─H functionalization, alkene modification, coupling reactions, and redox processes, along with relevant mechanistic insights and structure-activity relationships. While challenges remain in catalyst stability, structural diversity, and stereocontrol, manganese-based photocatalysis shows strong potential for enabling greener and more sustainable synthetic routes. By providing a clear, categorization-based overview, this review aims to encourage further developments in this rapidly evolving field.

Sonodynamic therapy (SDT) is a promising modality for anticancer and antimicrobial applications for deep seated wounds and infections. The boron-dipyrromethene based photosensitizers can be activated by ultrasound (US) for therapeutic applications of SDT. The estrone linked BODIPY were synthesized and characterized. The linker between estrone unit and boron-dipyrrin unit was varied from phenyl to thiophene rings. Estrone substituted BODIPYs exhibited noticeable red shifts (12-36 nm) in the absorption and emission maxima as compared to the meso-phenyl BODIPY (standard reference BODIPY), with relatively larger Stokes shifts (719-2095 cm^-1). TD-DFT calculation indicated significant intramolecular charge transfer from estrone linker unit to the boron dipyrrin unit. This study demonstrates the feasibility of using estrone linked BODIPYs sonosensitizers for antimicrobial sonodynamic therapy (SDT). Among them, EBD-1 exhibited the highest singlet oxygen quantum yield (∼90%) and demonstrated potent antibacterial activity, achieving ≥ 3 log₁₀ reduction (≥ 99.9%) in Escherichia coli (E. coli) viability under microbubble assisted sonodynamic therapy.

Herein, picolinamide (pica) and sulfur chelated Pt(II) complexes were focused to investigate for their bioactivity and cytotoxic property. For better anticancer activity and less toxicity of Pt(II) complex, l-cysteine (L-cys) and N-acetyl-l-cysteine (N-acetyl-l-cys) were used to synthesize Pt(II) complexes. Complex [Pt(pica)(OH₂)₂](NO₃)₂, C-2 was obtained on hydrolysis of [Pt(pica)Cl₂], C-1. The complex [Pt(pica)(l-cys)]⁺; C-3 and [Pt(pica)(N-ac-l-cys)]; C-4 were synthesized from C-2 with thiols l-cys and N-ac-l-cys, respectively. The binding activity of Pt(II) complexes with DNA and BSA were performed for their binding mode and binding constants. The binding modes of the Pt(II) complexes were executed by electronic and fluorescence spectroscopic methods. Synchronous and 3D fluorescence spectroscopic investigations were performed to observe the insight interaction and conformational change of BSA, when interacts with the complex. The drug likeness property was conducted by PASS prediction and ADMET software programs. Molecular docking of the complexes was carried out with DNA, HSA, and HER-2 cancer protein. The cytotoxic activity of the complexes was tested on breast cancer cell lines; MCF-7, MDA MB-231 and normal human embryonic kidney HEK293T cells. Necrotic cell death mechanism was confirmed by Annexin-V-FITC/PI assay by flow cytometric method and the production of reactive oxygen species (ROS) was assessed through DCFDA assay.

Spatial distribution of various functional groups in biologically active molecules greatly influences their affinity toward the targets. This spatial distribution can be regulated by external stimuli such as ultrasound, light, etc. Photoswitches are one such example, where light induces isomerization, which leads to the formation of another isomeric form with higher affinity, at a particular wavelength. In this regard, utilizing the isomerization across a double bond under UV or visible light, various small-molecule-based photoswitchable anticancer agents are being designed, that show greater antiproliferative activity in one isomeric form over the other. Herein, some of the recent advances made in this direction have been compiled, which are being developed as potent therapeutics for a spectrum of cancer types.

Hydrogen (H₂) has been considered as a potential alternative energy candidate because it has high energy storage capacity and no hazardous by-products are produced upon its combustion; the production of H₂ via the photocatalytic alcohol reforming has motivated a broad research interest. Here, we develop TiO₂ photocatalyst coupled with photoacid generator (PAG) for significantly augmented photocatalytic H₂ generation by catalytic reforming of neat methanol. The H₂ evolution rate over TiO₂-PAG is 1412.4 µmol g^-1 h^-1, which is 3.5 times higher than bare TiO₂ (397.4 µmol g^-1 h^-1). The optimal sample exhibits an apparent quantum yield (AQY) of 5.68% at λ = 365 nm. The enhancement of the photocatalytic performance is due to abundant H⁺ ions generated from α-hydrogen abstraction by PAG, which can be effectively combined with photoinduced electrons from TiO₂ and reduced to H₂. In addition, strong metal-support interaction (SMSI) between Pt and TiO₂ removes adsorbed H₂ from the surface of Pt─TiO₂, keeping the surface fresh and maintaining high efficiency and excellent recycling stability of obtained photocatalysts. The combination of the two emerging functional materials represents a simple but economical and powerful approach for highly efficient methanol photocatalytic reforming into hydrogen.

Lanthanides' luminescent thermometry operating in biological windows highlights its promising applications, constantly improving performances, and interesting new findings. This work presents two MOFs, a homometallic sample based on neodymium (1) and a heterometallic one including ytterbium cations (2) as thermometers in the physiological temperature range, operating in biological windows (BWs). These materials were developed with the aim of understanding their thermometric performance and to gain deep knowledge into the energy transfer between the mentioned cations. The homometallic sample achieved a maximum relative sensitivity (Sr) of 0.59%K^-1 at 20°C by using the luminescence intensity ratio (LIR) of the two components that contribute to the main emission band ca. 1060 nm, which is associated with the ⁴F_3/2 → ⁴F_11/2 transition. In the case of the heterometallic sample, interestingly, there is an increase in the intensity of the ytterbium cation emission as the temperature increases. This behavior was rationalized by means of theoretical calculations and matches other examples from the literature. The Yb^III/Nd^III intensity ratio achieves a maximum Sr 0.53%K^-1 at 20°C.

Carbohydrates are essential biomolecules that play critical roles in biological processes such as energy storage, cellular communication, and immune response regulation. Their structural complexity arises primarily due to the presence of various hydroxyl groups and stereocenters, which presents significant challenges for structural modification and functionalization. Traditional carbohydrate functionalization strategies often necessitate multiple protecting groups and harsh reaction conditions. This in turn limits their efficiency and synthetic flexibility. In recent years, transition metal catalysis, particularly palladium-mediated protocols, has emerged as a powerful tool for selective and efficient carbohydrate functionalization under mild conditions. Palladium catalysis has enabled diverse transformations, including glycosylation, C─C and C─X (X = O, N, S) bond formation, and regioselective derivatization, significantly expanding the chemical space of carbohydrates and glycoconjugates. This review provides a comprehensive analysis of recent advancements in palladium-catalyzed carbohydrate functionalization over the past 8 years, with a focus on synthetic strategies, mechanistic insights, and practical applications. By highlighting the latest developments and future directions, this review aims to serve as a valuable resource for the researchers working at the interface of carbohydrate chemistry, catalysis, and biomedical sciences.