Antibacterial, Antifungal and Ecotoxic Effects of Ammonium and Imidazolium Ionic Liquids Synthesized in Microwaves

Abstract

Ionic liquids are increasingly used for their superior properties. Four water-immiscible ionic liquids (butyltriethylammonium bis(trifluoromethylsulfonyl)imide, octyltriethylammonium bis(trifluoromethylsulfonyl)imide, dodecyltriethylammonium bis(trifluoromethylsulfonyl)imide, butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide) and their water miscible precursors (bromides) were synthesized in a microwave reactor and by conventional heating. The best conditions for microwave-assisted synthesis concerning the yield and the purity of the product are proposed. The heating in the microwave reactor significantly shortened the reaction time. Biocide and ecotoxic effects of synthesized ionic liquids and their precursors were investigated. All tested compounds had at least a little effect on the growth or living of microorganisms (bacteria or mold). The precursor dodecyltriethylammonium bromide was found to be the strongest biocide, but posed a risk to the aquatic environment due to its relatively high EC50 value in the test with Vibrio fischeri. We assumed that apart from the alkyl chain length, the solubility in water, duration of action, or type of anion can influence the final biocide and ecotoxic effect.

Ecotoxicity and Hemolytic Activity of Fluorinated Ionic Liquids

“…Furthermore, the urgent need to evaluate the antibacterial properties of ILs has also been noticed, in order to screen for new substances with potential pharmacological value that may represent a better alternative to traditional treatment and an advantage regarding the constant increment of antimicrobial resistances that hampers the treatment of several infections. The ability to inhibit the growth of several pathogens has been detected for several common imidazolium, pyridinium, ammonium, piperidinium and pyrrolidiniumbased ILs, among others [22,[24][25][26][27][28][29][30]. Moreover, it is well known that the increment of the alkyl side chain length plays a major role in the antimicrobial potency of ILs, which can be related to a mechanism of cell membrane disruption boosted by the higher hydrophobicity associated with longer alkyl chains-based compounds [27][28][29][30].…”

Tri-tert-butyl(n-alkyl)phosphonium Ionic Liquids: Structure, Properties and Application as Hybrid Catalyst Nanomaterials

“…The microstructure [37] and ecotoxicity of ILs [38,39] are emerging topics of much attention. The conjunction of hydrogen bonding and ionic interactions of the IL forces microstructural directionality.…”