LAUSR

Abstract This research investigates the influence of the subsituent's relative positions (ortho, meta, or para) of dicationic ionic liquids (ILs) on the catalytic production of 5-hydroxymethylfurfural (HMF). This research started with the facile synthesis of new dicationic ILs followed by its characterization using NMR, FT-IR, CHN, and UV–Vis. Then the acidity properties are measured using the Hammet method. The screening process revealed that the relative positions of substituents (ortho, meta and para) on the cationic site remarkably affect the overall catalytic performance. Highly efficient and selective dehydration of d -fructose to HMF was obtained using Bronsted ortho-IL with a fructose conversion of 95.7% and HMF yield of 90.5% after 60 min at 100 °C. The results revealed that the geometry of the isomer ILs influences the yield of HMF. The effects of reaction time, temperature, catalyst concentration and reusability of the dicationic ILs are studied in this work.