Bulletin of the Korean Chemical Society最新文献

A novel all-sequential-dip-coated (SDC) deposited FA₁MA_1−yPbI_3−xBr_x perovskite films have been synthesized from an aqueous non-halide lead precursor towards an environmentally benign, cost-effective, and efficient approach for high-performance perovskite solar cells (PrSCs). The mixed-cationic FA₁MA_1−yPbI_3−xBr_x perovskite layers ensure the fractional incorporation of Br into the perovskite crystal lattice. The insertion of Br contents was regulated by modulating the FABr concentration into the FABr/MAI mixed-cationic precursor solution. The incorporation of minor FABr into MAI helps to improve the surface coverage and crystallinity of the synthesized per-ovskite layer in contrast to the other perovskite films prepared with higher FABr content under the same environment. The PrSCs with these FA₁MA_1−yPbI_3−xBr_x perovskite layers displayed good de-vice performances and stability with a PCE of 11.1%. These outcomes reveal that the synthesis of FA₁MA_1−yPbI_3−xBr_x perovskite films with the SDC approach is more efficient because of the use of environmentally benign solvents for synthesizing lead and perovskite layers.

Precious metal complexes, which act as excellent photoredox catalysts, have now being replaced by earth-abundant metal complexes. This review focused on redox reactivity of ligand-to-metal charge transfer (LMCT) and metal-to-ligand charge transfer (MLCT) excited states of earth-abundant metal complexes. Iron complexes with strongly σ-donating NHC-ligands (NHC = N-heterocyclic carbene) has emerged, featuring long lived LMCT excited states due to a significantly increased barrier for deactivation via metal centered states. A Fe(III)-NHC complex acts as an effective photoredox catalyst for various photocatalytic redox reactions. Although manganese(IV)-oxo complexes have no long-lived excited states (τ < < 1 ns). Once acids such as Sc(OTf)₃ and HOTf are bound to the oxo moiety of Mn(IV)-oxo complexes, the photoexcitation of acid-bound Mn(IV)-oxo complexes resulted in formation of the excited states with microseconds lifetimes, which are capable of oxidation of substrates including benzene to phenol. Photoexcited states of Mn(III), Mn(II) and Mn(I) complexes act as photoreductants to reduce substrates including O₂. On the other hand, photoexcited states of Co(IV) and Co(III) complexes act as photooxidants, whereas those of Co(II) and Co(I) complexes act as photoreductants. With regard to the excited state lifetime, [Cr(tpe)₂]³⁺ (tpe = 1,1,1-tris(pyrid-2-yl)ethane) exhibited the longest luminescence lifetime (τ = 4500 μs), acting as an effective photoredox catalyst for photocatalytic redox reactions. The LMCT state of a Cr(0) complex acts as a super photoreductant. Thus, LMCT and MLCT excited states of earth-abundant metal complexes are utilized as strong photooxidants and photoreductants, respectively.

The field of coordination chemistry has evolved to intersect with organic chemistry and biochemistry, giving rise to the disciplines of organometallic and bioinorganic chemistry. Nuclear magnetic resonance (NMR) spectroscopy can be applied for characterizing transition metal complexes, spanning both diamagnetic and paramagnetic complexes prevalent in organometallic compounds and metalloproteins. This review offers a comprehensive overview of a wide variety of characterization techniques, ranging from basic ¹H and ¹³C NMR spectroscopy to advanced methods such as heteronuclear experiments, polarization transfer techniques, relaxometry, and multidimensional NMR spectroscopy. The diverse array of NMR spectroscopic methods outlined here promises to enhance our comprehension of transition metal complexes, facilitating the development of innovative catalysts and therapeutics.

Amino-single benzene-based fluorophores are representative small-size dyes with an electron push-pull structure on the benzene core. This paper provides a new library of amino-single benzene-based fluorophores with trifluoroacetyl moiety at the electron-pushing amine group.

The performance of perovskite solar cells (PSCs) is significantly governed by the interface of perovskite layer. Therefore, a great deal of attention has been paid to the interface engineering of perovskite layer to improve the performance of PSC. In the meantime, KCl is one of the popular molecules being utilized for the interface treatment between SnO₂ and perovskite. In this study, we investigate the effect of UV-ozone (UVO) treatment of KCl interlayer on the photovoltaic performance. A device employing UVO-treated KCl shows a higher power conversion efficiency mainly based on an increased open-circuit voltage (V_OC). Ultraviolet photoelectron spectroscopy analysis indicates that the UVO treatment induces a rearrangement of energy level at the interface, being responsible for the increase in V_OC. Accordingly, an increased charge recombination resistance is evidenced by impedance spectroscopy owing to the inhibited recombination at the SnO₂ and perovskite interface by the aid of the aligned energy level.

During the last decade, molecular diagnostics has become increasingly important, especially during the SARS-CoV-2 pandemic. Advances in droplet-based microfluidics, which divides samples into thousands of microdroplets, are responsible for high-throughput data provision, increased analysis sensitivity, and improved performance to overcome challenges in controlling diseases and early diagnosis. Different targets, such as nucleic acids, proteins, or single cells, can be detected and analyzed in terms of their characteristics in a much more extensive and precise manner with the integration of droplet microfluidics into various molecular diagnostic techniques. In this review, we explore recent advances in the development of droplet microfluidics-based molecular diagnostic techniques and future perspectives in the field.

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.