Dicationic Herbicidal Ionic Liquids Comprising Two Active Ingredients Exhibiting Different Modes of Action

Area of Science:

• * Agricultural Chemistry
• * Organic Synthesis
• * Weed Science

Background:

• * Development of novel herbicidal compounds is crucial for sustainable agriculture.
• * Herbicidal ionic liquids (HILs) offer a promising avenue for improved herbicide delivery and efficacy.
• * Combining herbicides with different modes of action can combat weed resistance.

Purpose of the Study:

• * To synthesize and characterize novel dicationic herbicidal ionic liquids (HILs).
• * To incorporate two distinct herbicidal anions: tribenuron-methyl (ALS inhibitor) and synthetic auxins (growth regulators).
• * To evaluate the efficacy and solvent affinity of the synthesized HILs.

Main Methods:

• * Synthesis of dicationic HILs using tetramethylene-1,4-bis(decyldimethylammonium) and dodecylmethylene-1,12-bis(decyldimethylammonium) cations.
• * Incorporation of herbicidal anions: tribenuron-methyl and various synthetic auxins (e.g., 2,4-D, MCPA).
• * Characterization of HILs' stability, solvent affinity, and herbicidal activity through greenhouse tests.

Main Results:

• * Synthesized HILs showed good affinity with polar and semipolar solvents, with limited solubility in ethyl acetate and hexane.
• * Most synthesized HILs exhibited greater herbicidal effectiveness than the reference tribenuron-methyl herbicide.
• * Longer alkyl chains in the cation (dodecylmethylene-1,12-bis(decyldimethylammonium)) resulted in enhanced herbicidal effects.

Conclusions:

• * Novel dicationic HILs were successfully synthesized, integrating multiple herbicides into a single molecule.
• * The developed HILs demonstrate enhanced herbicidal efficacy and potential for reduced weed resistance.
• * Cation structure and herbicidal anion combination significantly influence HIL performance.