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

Area of Science:

• Environmental Chemistry
• Ecotoxicology
• Green Chemistry

Background:

• Functionalized ionic liquids (FILs) are emerging chemicals with diverse applications.
• Understanding their environmental fate and biological impact is crucial for safe development.
• Phytotoxicity assessments are vital for evaluating risks to terrestrial ecosystems.

Purpose of the Study:

• To evaluate the environmental behavior and phytotoxicity of FILs with varied cation substituents and fluorinated anions.
• To establish structure-activity relationships linking FIL properties to their ecotoxicity.
• To provide design principles for safer, greener ionic liquids.

Main Methods:

• Soil bioassays using *Raphanus sativus* (radish) to determine phytotoxicity (EC50).
• Measurement of physicochemical properties: water solubility, surface tension, molecular volume.
• In-silico modeling for lipophilicity (log Kow) and bioconcentration factor (log BCF).

Main Results:

• FIL lipophilicity and bioaccumulation correlated with plant growth inhibition.
• Increased fluorination, anion size, and charge delocalization enhanced hydrophobicity, bioaccumulation, and toxicity.
• FILs with linear cations were more toxic than those with cyclic cations.
• Antioxidant responses in plants indicated oxidative stress as a toxicity mechanism.

Conclusions:

• FIL phytotoxicity is predictable based on structural features like cation type and anion fluorination.
• Hydrophobicity, bioaccumulation, and molecular asymmetry are key drivers of FIL toxicity.
• This study provides a framework for designing safer FILs, prioritizing reduced environmental risk.