Bulletin of the Korean Chemical Society最新文献

We demonstrate the morphology and spectral properties of silver-coated gold nanorods (AuNRs@Ag), synthesized via seed-mediated growth, using scanning electron microscopy (SEM) and dark-field (DF) spectroscopy. The relationship between surface damping and the thickness of the Ag shell in AuNRs was analyzed at the single-particle level. Additionally, we adjusted the bulk damping and radiation damping of AuNRs to elucidate the contribution of surface damping. SEM images demonstrated an increase in length and width following Ag deposition. Elemental mapping analysis confirmed the Ag deposition on the AuNR surface, with Ag content measured at 26.7% for AuNR@Ag_26.7 with a 1-day incubation period and 34.8% for AuNR@Ag_34.8 with a 2-day incubation period. DF spectroscopy revealed a notable blue shift and slight broadening in their LSPR spectra. Moreover, surface damping decreased with an increase in Ag content. Consequently, this study advances the understanding of plasmon damping mechanisms in single AuNR@Ag for their potential applications.

The pyrazole ring structure is extensively spotted as a pharmacophore and fortify-cation of the modern organic synthesis toolbox, which demands synthetic tactics to generate its derivatives. Especially, pyrazolo-pyrimidinones are crucial part to synthesize phosphodiesterase type 5 (PDE5) such as sildenafil and lodenafil. Herein, we report a simple and efficient route for Sildenafil and derivatives from easily available materials.

The cover image depicts a post-combustion CO2 capture process using a MOF-74 type framework functionalized with diamine groups to enhance the interaction with incoming CO2 molecules. Modified with hydrophobic components, these frameworks are excellent for CO2 capture while maintaining structural integrity even under humid conditions. More details are available in the article by Jintu Francis Kurisingal, Jong Hyeak Choe, Hyojin Kim, Jeongwon Youn, Gayoung Cheon, Chang Seop Hong

Three novel non-fullerene acceptors (NFAs) (PhBu-IDT-BT-IC, PhBu-IDT-BT-IC4F and PhBu-IDT-BT-IC4Cl) based on 3,8-dioctyl-indaceno[1,2-b:5,6-b’]dithiophene (IDT) core have been designed and synthesized with and without halogen (F and Cl) substitution. The NFAs showed high thermal stability. The ultraviolet–visible absorption studies in solution and thin film for the three acceptors revealed maximum absorption from 687 to 732 nm and 731 to 847 nm, respectively. The onset of absorption in the thin film was found to be extending up to around 960 nm for PhBu-IDT-BT-IC4Cl. The optical band gap ranged from 1.30 to 1.41 eV, which are very low and useful for photovoltaic application. The introduction of halogen appreciably altered the LUMO energy levels, whereas the HOMO energy levels were nearly intact. These small molecule non-fullerene acceptors could be used as potential acceptors in bulk heterojunction organic photovoltaic (BHJ-OPV) applications.

Estimating binding affinity is a crucial step in the drug discovery process. In computer-aided drug design, this challenge can be divided into two main tasks: finding the correct binding pose and estimating the binding free energy. In this study, we propose a new binding affinity estimation protocol that utilizes molecular docking with limited experimental data and estimates binding affinity using molecular dynamics simulation. A custom scoring function was employed during docking to identify an improved initial binding pose, and the linear interaction energy method with an optimized coefficient was used for binding affinity estimation. The protocol was validated with an external data set and applied to modafinil and its derivatives to rank their binding affinities to adenosine A2A receptors (ADORA2A) as a case study. This approach could be both time-efficient and valuable for computational drug discovery, particularly when experimental data is limited.

Hydrogen sulfide (H₂S) and nitroreductases (NTR) are key biological reductants, with H₂S acting as a key signaling molecule and NTR reducing nitro groups to amines in cellular metabolism. Visualizing these reducing components, often overexpressed in cancer cells or bacterial environments, is crucial for metabolic understanding. Existing fluorescent probes detect these individually, but simultaneous detection methods are unexplored. We designed probe 1, which shows high fluorescence only when both NTR and H₂S are overexpressed. The probe transformed into benzothiazole-fused coumarin by NTR, exhibiting fluorescence, and shows a stronger signal in the presence of both NTR and H₂S, making it a potential tool for detecting their simultaneous overexpression.

In the last few decades, fullerene-based acceptors have been extensively utilized in organic solar cells (OSCs). However, OSCs based on fullerenes suffer from low photocurrent and photovoltage due to their poor light absorption capacity and limited tunability of energy levels, which impedes efficiency improvements. Recently, non-fullerene acceptors (NFAs) have enabled rapid progress in OSCs, owing to their favorable properties such as strong light absorption, facile energy level tuning, and improved charge transport characteristics. These features have led to rapid efficiency enhancements. This review discusses the latest research trends related to NFAs, covering several factors that can be applied in the development of NFAs. Finally, we suggest prospects and challenges for high-performance NFA-based OSCs on the path to commercialization.

TiO₂ photocatalysts were synthesized by simple sol gel method and annealed at 300, 500, and 600°C. Photocatalytic performance of as-prepared TiO₂ and annealed TiO₂ samples was evaluated for the decomposition of acetaldehyde under UV light irradiation. TiO₂ annealed at 500°C (T500) showed the highest acetaldehyde removal performance, which was attributed to combined effects of its crystallinity, defect density, surface area, narrow band gap with the dual phase of TiO₂, and lifetimes of charge carriers. In humid conditions, overall acetaldehyde removal performance of T500 slightly decreased, but the extent of total oxidation of acetaldehyde into CO₂ increased in high humidity as compared to dry conditions. Moreover, fixation of T500 on mica sheet using binders resulted in promising photocatalytic performance, making it a potential candidate for air purification applications. Fourier-transform infra-red (FT-IR) analysis confirmed the stable existence of binder structure under dry air and UV treatment, which is crucial for real applications.

This review describes the application of nuclear magnetic resonance (NMR) spectroscopy in characterizing transition metal complexes. By utilizing NMR spectroscopy on both diamagnetic and paramagnetic transition metal complexes, extensive insights into their geometric, electronic, and magnetic properties are obtained. Enhancing our comprehension of NMR spectra broadens the analytical techniques available for studying transition metal complexes in organometallic and bioinorganic chemistry. More details are available in the article by Jeongcheol Shin, Mi Hee Lim, Jiyeon Han.

Glutamine-addicted cancer metabolism is recently recognized as novel cancer target especially for KRAS and KEAP1 co-occurring mutations. To identify more drug-like GLS inhibitors, we report the amides in the wing macrocycles for GLS inhibition with unique SAR analysis. Although the amidotriazoles (amides in the wing) are in general less potent than those of acylaminothiadiazole analogs (reverse amides in the wing), macrocycle 4, 5, and 7 are selected as a potent macrocyclic GLS inhibitor in both biochemical and cell viability assays. Selected molecules result in partial reduction in intracellular glutamate levels in LR (LDK378-resistant) cells which is consistent to their cells viability result. Finally, selected compounds reduce the growth of A549 and H460 cells which have co-occurring mutations including KRAS and KEAP1. The putative binding mode of macrocycle 4 is also suggested using a molecular docking model.