10th U6+ Consortium of African Universities International Conference

This is the first report on the antimicrobial evaluation of tetrafluorinated azobenzene-imidazolium salts with various spacer length. All salts qualified as ionic liquids crystals (ILCs) which melted below 100 ⁰C. The functionalized azobenzene moiety was connected to the imidazolium head via a methylene spacer of varying length (n = 3-12). The ILCs were characterized using FTIR, NMR spectroscopy, and elemental microanalysis. Their antimicrobial potential against Staphylococcus aureus, Escherichia coli, Samonella typhi, Candida albicans and Saccaromyces was evaluated using the disc diffusion method. Antimicrobial properties of these ILCs was dependent on the spacer length. The ILCs were selectively active against the tested microorganisms with zone of inhibition diameters ranging from 7mm-15mm. Their biological efficacy was dependent on the spacer length. The presence of the connecting long alkyl chains is essential for the ILCs to exhibit microbial efficacy. Active ILCs on Staphylococcus aureus contained 3 to 12 carbons in the spacer length while the compounds with the shorter chain length exhibited no activity against Escherichia coli. Difference in antimicrobial behavior of the ILCs could be due to the different cell wall between the Gram positive and negative bacteria. The synthesized compounds may serve as a new strategy for the design and development of effective therapeutics.