Novel herbicidal ionic liquids (HILs) containing different anions and cations derived from ammonium esterquats were prepared by employing a simple, inexpensive pathway. The basic physicochemical properties of the synthesized salts (such as density, viscosity, refractive index, solubility and thermal stability) were determined.Additionally, their herbicidal efficacy was evaluated under greenhouse and field conditions with a subsequent assessment of biodegradability and toxicity (acute oral toxicity towards rats and rainbow trout, the growth inhibition test of green algae and the acute immobilization test using water flea). The results of greenhouse and field experiments revealed that the herbicidal activity of HILs comprising long alkyl chains has exceeded that of commercial plant protection products. The HIL containing the di(tallowoyloxyethyl)dimethylammonium cation exhibited notable biodegradability (63% after 28 days) and various toxicity classifications depending on the tested organism: category V towards rats with LC 50 4 2000 mg, category II towards fish with LC 50 /96 h at 10.62 mg L À1 , category I towards algae and daphnids with E r C 50 /72 h at 1.73 mg L À1 and EC 50 at 0.28 mg L À1 , respectively. These findings provide evidence that the synthesis of HILs with a specifically designed structure may be successfully employed for obtaining novel, efficient and environmentally friendly plant protection agents. † Electronic supplementary information (ESI) available: 1 H and 13 C NMR spectra, detailed testing procedures for: the acute toxicity test towards rats, the acute oral toxicity test towards rainbow trout, the growth inhibition test of green algae, the acute immobilization test using water flea. See

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In this study, fourteen new herbicidal ionic liquids (HILs) based on MCPB with a 1-alkyl-1-methylpiperidinium cation were synthesized and characterized.

This study focused on the synthesis and subsequent characterization of herbicidal ionic liquids based on betaine and carnitine, two derivatives of amino acids, which were used as cations. Four commonly used herbicides (2,4-D, MCPA, MCPP and Dicamba) were used as anions in simple (single anion) and oligomeric (two anions) salts. The obtained salts were subjected to analyzes regarding physicochemical properties (density, viscosity, refractive index, thermal decomposition profiles and solubility) as well as evaluation of their herbicidal activity under greenhouse and field conditions, toxicity towards rats and biodegradability. The obtained results suggest that the synthesized herbicidal ionic liquids displayed low toxicity (classified as category 4 compounds) and showed similar or improved efficacy against weed compared to reference herbicides. The highest increase was observed during field trials for salts containing 2,4-D as the anion, which also exhibited the highest biodegradability (>75 %).

Herbicidal ionic liquids (HILs) have been demonstrated to have potential as highly effective herbicides that may also have different modes of action that their neutral precursors. Here, double salt herbicidal ionic liquids (DSHILs) containing at least two herbicidal anions selected from glyphosate, dicamba, or 4-chloro-2-methylphenoxyacetate (MCPA) paired with ammonium or phosphonium cations are reported along with their post-emergence herbicidal activity against several plant species, from both greenhouse and field study-based bioassays. The novel DSHILs were shown to integrate the advantages of two different herbicides into a single HIL, enhance herbicidal efficacy, and reduce the risk of weed resistance due to the various modes of action of the applied treatment. The formation of the DSHILs dramatically reduced melting points and modified the compound solubilities compared to the parent herbicides. Statistical analyses for the greenhouse efficacy tests demonstrated that DSHILs had significant positive differences against winter wheat (Triticum aestivum L.) and white mustard (Sinapis alba L.) as compared to commercial formulations. Biodegradability studies were also performed on selected DSHILs, and the compounds were found to be not readily biodegradable.