Synthesis of multifunctional di-cationic ionic liquids: Unveiling antibacterial activity across diverse strains

The increasing prevalence of antibiotic resistance poses a significant global risk to public health. Therefore, there is an urgent necessity to discover innovative antibacterial materials. In this study, we introduced a novel synthesis method that yielded 18 unique di-cationic ionic liquids (DILs), intricately crafted through a fusion of quaternization and metathesis reactions. These innovative compounds boasted imidazolium, pyridinium, and quaternary ammonium as their cationic constituents, accompanied by acetate and bisulfate ions as their anionic counterparts. The incorporation of spacer chains, specifically trans-1,4-dibromo-2-butene and alpha, alpha '-dibromo-p-xylene, facilitated the synthesis of these di-cations. Thorough characterization of the synthesized DILs was conducted using advanced spectroscopic techniques, including FTIR and nuclear magnetic resonance, ensuring a comprehensive understanding of their structural attributes. The central objective of this research was to assess the effectiveness of these DILs in combating a diverse spectrum of resilient bacterial strains commonly encountered in various environmental settings. This evaluation encompassed both gram-positive and gram-negative species. (c) 2024 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). https://doi.org/10.1063/5.0224274