Difunctional ammonium ionic liquids with bicyclic cations†
The increasing limitations regarding the applied amounts of plant protection make hybrid ionic liquids an interesting class of compounds belonging to the III generation ILs. There are known examples of biologically active compounds in the literature, the structure of which is based on a monoalkyl derivative of 1,4-diazabicyclo[2.2.2]octane (DABCO). In the framework of the presented study, an efficient three-step method was developed for the synthesis of novel bicyclic herbicidal ionic liquids in which an alky derivative of DABCO was used as the cation and the 4-chloro-2-methylphenoxyacetic anion originated from a commonly applied herbicidal acid, MCPA. The synthesized new ILs were purified and identified and their surface activity, thermal stability and solubility were characterized. Furthermore, their herbicidal activity under greenhouse conditions towards common weed species present in agricultural crops and antimicrobial properties were also evaluated. The high biological activity of the synthesized ILs was correlated with their surface active properties. The obtained results confirmed the dual functionality of the synthesized herbicidal ionic liquids.