Designing Safer Functionalized Ionic Liquids: Monoterpene-Derived Compounds for Greener Agrochemical Development

High Resolution Image Download MS PowerPoint Slide The environmental behavior and phytotoxicity of functionalized ionic liquids (FILs) featuring imidazolium cations bearing a cyclic (−)-menthol or a linear 1-decanol-derived substituent and fluorinated anions were evaluated in a soil bioassay ( Raphanus sativus ). Structure–activity relationships were determined by integrating measurements (water solubility, surface tension, molecular volume) with in-silico descriptors ( n -octanol–water partition coefficient, log K OW; bioconcentration factor, log BCF; asymmetry). Lipophilicity and bioaccumulation correlated with fresh-mass inhibition (EC 50 ). More-fluorinated, larger, and charge-delocalized anions were more hydrophobic, elevating bioaccumulation and toxicity. Within menthol-based series, sulfonylimide-based FILs were more phytotoxic (EC 50 74.7, 107.3 mg·kg –1 soil dry weight) than sulfonate analogues (e.g., 299.1 mg·kg –1 ). FILs with linear cations were more phytotoxic and showed higher log K OW /BCF than cyclic analogues, consistent with greater molecular volume, higher asymmetry, and reduced hydration. Antioxidant responses paralleled EC 50, implicating oxidative stress. This workflow improves risk assessment and provides green-by-design criteria to prioritise safer ILs.