Search Results (4)

This study investigates the antibacterial N-heterocyclic carbene (NHC)–silver complexes using the SwissADME platform, a web-based tool developed by the Swiss Institute of Bioinformatics (SIB). NHCs, particularly their silver complexes, have gained significant interest in medicinal chemistry for their potential as antibacterial and anticancer agents. The effectiveness of these complexes is closely linked to their structure, including factors like lipophilicity, which enhance their ability to penetrate bacterial cells and sustain the release of active silver ions. SwissADME provides computational estimates of pharmacokinetic properties, including absorption, distribution, metabolism, and excretion (ADME) characteristics, as well as drug-likeness and toxicity assessments. By evaluating parameters like molecular weight, topological polar surface area, lipophilicity (LogP), and water solubility, SwissADME offers insights into the drug-like potential of compounds. This study is inspired by a comprehensive review of antibacterial NHC–silver complexes published from 2006 to 2023, which identified superior structures with notable biological activity. The primary aim is to determine whether these active complexes exhibit distinct SwissADME parameters compared to others, providing a deeper understanding of the factors that influence their biological efficacy and aiding in the identification of promising drug candidates. Finally, experimental stabilities of exemplary complexes were confronted with absolute LUMO values derived from DFT calculations. Full article

Introduction: N-heterocyclic carbenes (NHCs) are considered important preferred auxiliary ligands for transition metals due to their strong σ-donor and weak π-acceptor properties and ease of structural modification in catalyst design. The functionalization of NHC by adding different substituent groups is an effective strategy for designing complexes with desired electronic and steric properties. NHC–Pd complexes are of particular importance due to their resistance to air, moisture and heat and their strong stability under catalytic and biological conditions. It is known that NHC–Pd complexes show excellent performance in the Suzuki–Miyaura cross-coupling reaction. The traditional Suzuki–Miyaura reaction involves the cross-coupling reaction of alkyl and arylboronic acids with aryl halides. This reaction has some advantages over other C-C coupling reactions. The use of water as a suitable and reliable solvent in the reaction, the fact that the reaction products are generally poorly soluble in water and can be easily separated from the reaction mixture, the use of non-toxic chemicals, the moderation of reaction conditions, and good functional group compatibility make it useful and worth studying. There are many examples of studies on the application of NHC–Pd complexes in the Suzuki–Miyaura reaction in aqueous media, and the highly effective catalytic activities and versatility of these reactions have been proven. Methods: In this study, a series of benzimidazole-based Pd–NHC complexes were synthesized. The synthesized complexes were characterized by spectroscopic methods. All complexes were tested as catalysts in the Suzuki–Miyaura cross-coupling reaction. Results: According to the obtained results, the synthesized benzimidazole-based Pd–NHC complexes were found to have high catalytic activity in the Suzuki–Miyaura cross-coupling reaction. Conclusions: The synthesized NHC-Pd complexes can be used as potential catalysts due to their high catalytic activity. It is thought that these catalysts can be used in different biochemical studies in the future. Full article

Copper-centered carbene–metal–halides (CMHs) with cyclic (alkyl)(amino) carbenes (CAACs) are bright phosphorescent emitters and key precursors in the synthesis of the highly promising class of the materials carbene–metal–amides (CMAs) operating via thermally activated delayed fluorescence (TADF). Aiming to reveal the molecular geometry for CMH phosphors in the absence of the intermolecular contacts, we report here the equilibrium molecular structure of the (CAAC)Cu(I)Cl (1) molecule in the gas-phase. We demonstrate that linear geometry around a copper atom shows no distortions in the ground state. The structure of complex 1 has been determined using the electron diffraction method, supported by quantum chemical calculations with RI-MP2/def2-QZVPP level of theory and compared with the crystal structure determined by X-ray diffraction analysis. Mean vibrational amplitudes, u_ij,h1, and anharmonic vibrational corrections (r_ij,e • r_ij,a) were calculated for experimental temperature T = 20 °C, using quadratic and cubic force constants, respectively. The quantum theory of atoms in molecules (QTAIM) and natural bond order (NBO) analysis of wave function at MN15/def2TZVP level of theory revealed two Cu^…H, three H^…H, and one three-center H^…H^…H bond paths with bond critical points. NBO analysis also revealed three-center, four-electron hyperbonds, (3c4e), [π(N–C) n_π(Cu) ↔ n_π(N) π(N–Cu)], or [N–C: Cu ↔ N: C–Cu] and n_π(Cu) → π(C–N)* hyperconjugation, that is the delocalization of the lone electron pair of Cu atom into the antibonding orbital of C–N bond. Full article

A series of ruthenium(II) complexes with N-heterocyclic carbene (NHC) ligands of the general type (arene)(NHC)Ru(II)X₂ (where X = halide) was prepared, characterized, and evaluated as antibacterial agents in comparison to the respective metal free benzimidazolium cations. The ruthenium(II) NHC complexes generally triggered stronger bacterial growth inhibition than the metal free benzimidazolium cations. The effects were much stronger against Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) than against Gram-negative bacteria (Escherichia coli, Acinetobacter baumannii, Pseudomonas aeruginosa), and all complexes were inactive against the fungus Candida albicans. Moderate inhibition of bacterial thioredoxin reductase was confirmed for selected complexes, indicating that inhibition of this enzyme might be a contributing factor to the antibacterial effects. Full article