title: Toxicity of various anions associated with methoxyethyl methyl imidazolium-based ionic liquids on Clostridium sp.
abstract: We investigated the effects on the growth of the anaerobic bacterium, Clostridium sp., of the ionic liquid, 1-methoxyethyl-3-methyl imidazolium [MOEMIM](+), derived from imidazolium cation and paired with one of a variety of counter-ions, viz., tetrafluoroborate [BF₄]⁻, hexafluorophosphate [PF₆]⁻(,) trifluoroacetate [CF₃COO]⁻, bis(trifluoromethane)sulfonamide [Tf₂N]⁻, methane sulfonate [OMS], and 1-butyl-3-methyl imidazolium tetrafluoroborate [BMIM][BF₄]. These anions, in association with [MOEMIM](+) lowered the growth rate of the bacterium, showing the following trend: [Tf₂N]⁻ ≧ [PF₆]⁻ > [BF₄]⁻ > [CF₃COO]⁻ > [OMS]⁻. Anions incorporating fluorine were more toxic than those without it, and their toxicity rose with an increase in the number of fluorine atoms. Also, [MOEMIM](+)[BF₄]⁻ was less toxic than [BMIM](+)[BF₄]⁻, probably due to the presence of a methoxyethyl functional group integrated in the cation side chain.
authors.affiliation: Department of Chemistry and Environmental Sciences, New Jersey Institute of Technology, Newark, NJ 07104, USA.
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
authors.forename: Sanjay V
authors.initials: SV
authors.lastname: Malhotra
authors.forename: Arokiasamy J
authors.initials: AJ
authors.lastname: Francis
mesh_terms: D000838:Anions / Q000737:chemistry / Q000633:toxicity; D001673:Biodegradation, Environmental; D003013:Clostridium / Q000187:drug effects* / Q000254:growth & development; D004305:Dose-Response Relationship, Drug; D055772:Green Chemistry Technology; D006863:Hydrogen-Ion Concentration; D007093:Imidazoles / Q000737:chemistry / Q000633:toxicity*; D052578:Ionic Liquids / Q000737:chemistry / Q000633:toxicity*
chemical_list: C419324:1-butyl-3-methylimidazolium tetrafluoroborate; D000838:Anions; D007093:Imidazoles; D052578:Ionic Liquids