ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Synthesis and fungicidal activity of imidazole dicyanamide ionic liquids

Jingyu Zhao and Haixiang Gao

Department of Applied Chemistry, China Agricultural University, Beijing, China

E-mail: hxgao@cau.edu.cn

Received: 24 March 2022  Accepted: 16 June 2022

Abstract:

Three 1-alkyl-3-methylimidazolium dicyanamide ([C_nmim][N(CN)₂]) ionic liquids were synthesized through anion-exchange reaction and characterized by FT-IR, ¹H-NMR and ¹³C-NMR spectroscopy and by differential scanning calorimetry. Their determined solubilities in common solvents of different polarity and surface tension were proved to be related to the length of their alkyl side chain. In antifungal toxicity screening, 1-decyl-3-methylimidazolium dicyanamide, [C₁₀mim][N(CN)₂], was tested against five common agricultural fungi, Valsa mali, Pythium aphanidermatum, Rhizoctonia solani, Phytophthora capsici and Alternaria solani. Since [C₁₀mim][N(CN)₂] exhibited an excellent effect on Valsa mali with a 100% inhibition rate, this fungus was selected for structure–activity relationship studies. Comparing the effect of the alkyl chain in [C_nmim][N(CN)₂] revealed that imidazolium cations with longer carbon chains had better fungicidal activity. On the other hand, anions may also have influence on the fungicidal activity, but the factor and causes need further studies.

Keywords: Ionic liquid; Fungicide; Valsa mali; 1-alkyl-3-methylimidazolium dicyanamide

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-022-02333-7

Chemical Papers 77 (1) 101–107 (2023)