Bis(ammonium) ionic liquids with herbicidal anions

Abstract

The method of synthesis of the novel bis(ammonium) herbicidal ionic liquids with the cation containing two quaternary nitrogen atoms was described. New compounds, containing three structurally different linkers, were prepared via acid–base reaction between the corresponding bis(ammonium) hydroxides and herbicides in the form of free acids. In addition, phase transitions, thermal stability and solubility in common solvents were determined. The herbicidal efficacy was tested in greenhouse experiments, wherein test plants were lambsquarters (Chenopodium album L.) cornflower (Centaurea cyanus L.), white mustard (Sinapis alba L.) and winter rape (Brassica napus L.). The biological activity of the anion (2,4-D, MCPA, Mecoprop, Dicamba) in all new HILs was preserved. Moreover, the efficacy of some salts was several times higher when compared to commercial formulations.