Bulletin of the Korean Chemical Society最新文献

The optimization of photoluminescence (PL) spectral bandwidths in InP-based colloidal quantum dots (QDs) faces limitations with traditional synthetic methods. This study introduces a novel approach utilizing light-induced thiolate ligand detachment to selectively precipitate QDs within an ensemble, triggered by photons whose energy matches the red tail of the band-edge absorption peak. We demonstrate that incorporating benzoquinone as an electron acceptor under inert conditions crucially enhances the efficiency of photoexcited hole-induced ligand detachment. Through careful optimization of laser exposure conditions, we successfully narrowed the PL bandwidth of InP/ZnSe/ZnS QDs from 39 to 35 nm. Our findings offer significant insights into the development of high-performance QD-based displays, promising advancements in color purity.

Dynamic nuclear polarization (DNP) offers significant signal enhancement compared to conventional nuclear magnetic resonance (NMR) in measuring the nuclear Overhauser effect. Owing to this enhancement, DNP enables the quantitative analysis of solvent–solute interactions, which are typically challenging to assess using standard NMR techniques. However, current experimental setups generally require the use of samples with relatively high solute concentrations because of large dilution factors. This limits the studies on solvent–solute interactions for bio-related molecules, particularly those with low solubility. In such cases, the concentration of solute post-dilution often falls below the detection limits. Herein, we introduce a novel dual injection system designed to considerably increase the dilution factor, thereby enabling the use of samples with lower solute concentrations while maintaining detectable signal levels. The effectiveness of this system was demonstrated in experiments using trifluoroacetic acid at concentrations 50 times lower than those used in the conventional method.

Biomolecular phase separation, a complex phenomenon within living systems, has garnered significant interest due to its diverse roles in cellular organization and function. Despite its importance, studying phase separation dynamics experimentally, particularly in the early stages, poses challenges. Our study investigates the dynamics of biomolecular phase separation using a graph-based simulation module, particularly emphasizing its early stages. Through a simplified model, we dissect the influences of various factors on collective behavior, highlighting the crucial role of combinatorial entropy in percolation dynamics. This study offers valuable insights into the fundamental principles governing biomolecular phase separation, with implications for understanding cellular processes and disease mechanisms.

While a pharmaceutically intriguing scaffold, 5,6-dihydropyrrolo[2,1-a]isoquinoline (DHPIQ), has precedently been prepared from diverse tetrahydroisoquinolines (THIQs) using elaborate conditions, convenient metal-free methods were discovered from condensation of cyanomethylene-THIQ (1) and α-halo-ketones or aldehydes (1a) to afford 15 DHPIQs (2–16) in moderate yields by employing unique reactivities of the secondary amine and α-carbon to the nitrile of 1. Preliminary biological studies with chronic myelogenous leukemia K562 and adriamycin-resistant K562 (K562/ADM) cells exhibited some of the DHPIQs tested were active in the both cell lines. In particular, cyclohexyl-fused DHPIQ (10) showed GI₅₀ values of 9.79 and 13.60 μM in K562 and K562/ADM cells, respectively. Based on the flow cytometry analysis of 10, the anti-cancer activity could be from apoptosis-related mechanisms. Overall, this DHPIQ scaffold may be further optimized to discover clinically meaningful anti-leukemic agents overcoming adriamycin resistance.

A new potential energy surface for forming glycine in the gas phase, starting from association of aminoacetonitrile (NH₂CH₂CN) with OH followed by subsequent hydrolysis, was determined using CBS-QB3 calculation. The overall activation energy was 90 kJ mol⁻¹ or 0 without or with catalytic H₂O, respectively. Alanine or serine was formed from 2-aminopropionitrile (CH₃CH(NH₂)CN) or 2-amino-3-hydrxypropionitrile (HOCH₂CH(NH₂)CN) instead of aminoacetonitrile with the overall activation energies of 89 or 49 kJ mol⁻¹, respectively. When an additional H₂O was involved in each reaction as a catalyst, barrierless reaction pathways were obtained. These results suggest that it is possible for investigated reactions to occur in interstellar ices along the proposed pathways, taking kinetic aspects into account.

Two new monopyridyl-based Anthracene and Pyrene ligands were synthesized and employed to design Ruthenium-coordinated organometallic complexes, RuAnthra and RuPyrene, respectively. The ligands and their metal complexes were fully characterized by different analytical techniques, including multinuclear 1D- and 2D-NMR, electrospray ionization-mass spectrometry, UV–Vis, fluorescence spectroscopy, and elemental analysis. Furthermore, their photophysical properties were studied in different solvents with increasing polarity using UV–Vis and fluorescence spectroscopy, showing less or no significant solvolysis effect. The average emission lifetimes of the complexes were further determined using time-resolved emission spectroscopy. Additionally, the ligands and their metal complexes showed excellent ability to generate singlet oxygen and can be useful for several important potential applications.

Plasmonic nanoparticles exhibit dramatic changes in optical properties depending on their spatial organization. Therefore, the ability to precisely control their assembly structure is important for both fundamental understanding and practical applications. In this personal account, we describe a templated surfactant-assisted seed-growth method to synthesize core–shell-type gold nanoparticle assemblies with controllable surface morphologies and optical properties. This approach provides a simple procedure for simultaneous growth and assembly of metal nanoparticles on polymer templates, producing well-defined nanostructures such as spiky nanoshells and raspberry-like metamolecules with useful and interesting optical properties, such as strong and uniform surface-enhanced Raman scattering and metamaterial properties. We discuss the factors that control the morphology and collective properties, describe the design rules acquired from the system, and suggest future directions of this research area.

The tumor-suppressing phosphorylation cascade is primarily regulated by transcriptional enhanced associate domain (TEAD) transcription factors, and the overexpression of these factors is associated with tumorigenesis and cancer progression. The central pocket of TEAD protein can be targeted by noncovalent inhibitors, and therefore, investigating the interaction patterns for TEAD and its available inhibitors seems essential. In this regard, molecular dynamics simulations were conducted to identify the most potent TEAD3 noncovalent inhibitors and to study TEAD3–inhibitor interaction patterns. We developed a 3D-quantitative structure–activity relationship model to investigate the structure–activity correlation for the available TEAD3 inhibitors. Our results indicated the role of Tyr230, Val317, Thr333, Met367, Cys368, Met371, Phe394, Ile396, Gln398, and Phe416 residues in TEAD3–inhibitor interactions. Dihydropyrazolo pyrimidines and compound 2 were identified as the most potent TEAD3 noncovalent inhibitors. The Comparative Molecular Field Analysis model analysis identified the hydrophobic-favored regions around the pyrazolo[1,5-a]pyrimidin-7(4H)-one ring and the unfavored steric regions around cyclohexane and phenyl groups of dihydropyrazolo pyrimidines.

The cover picture illustrates metal-organic frameworks (MOFs) being used as fluorescent probes to detect biomarkers in human urine. MOF-based fluorescent probes facilitate the diagnosis of diseases, including pheochromocytoma, toluene exposure, vitamin deficiencies, gout, hyperuricemia, cancers, various body disorders, and teratogenic effects, with low detection limits. Unlike conventional disease diagnosis methods such as biopsies or blood collection, detecting pathogenic biomarkers in human urine is non-invasive and carries less risk. More details are available in the article by Seyeon Jeong and Hoi Ri Moon.

Atomically precise metal nanoclusters (NCs) have emerged as a new frontier in electrocatalysis, enabling the study of electrocatalytic reactions on well-defined stable surfaces and rational electrocatalyst design based on atomic-level tailoring. In this review, we focus on the recent applications of these NCs to energy conversion reactions, including those involved in water splitting (hydrogen and oxygen evolution reactions), fuel cell operation (oxygen reduction and hydrogen oxidation reactions), and electrochemical CO₂ reduction. Emblematic examples are used to highlight the roles of different NC parts, for example, core metal and surrounding ligands, and the significance of the electrode substrate. Finally, we discuss the perspectives of the future development and implementation of NC-based energy conversion systems.