Ionic liquids of imidazolium salts comprising hexamolybdate cluster: Crystal structures and characterization

The present work reports on the synthesis, crystal structure, thermal stability, conductivity and electrochemical behaviors of three new metal-containing ionic liquids(MILs) [CnH2n+1-mim]2[Mo6O19] (n=14, 16, 18) (mim=methylimidazole). Each [Mo6O19]2− is sandwiched among the four imidazolium rings in one layer, and connects to the imidazolium heads in neighboring layer through hydrogen bonds. The MILs bulk-modified carbon paste electrode showed good electrocatalytic activity towards the reduction of bromopropionic acid. [Display omitted] •The work reports electrochemical behaviors of new metal-containing ionic liquids. The present work reports on the synthesis, crystal structure, thermal stability, conductivity and electrochemical behaviors of three new metal-containing ionic liquids(MILs) [CnH2n+1-mim]2[Mo6O19] (n=14, 16, 18) (mim=methylimidazole). Their structures were characterized by X-ray crystallography, IR spectroscopy and elemental analysis. The crystal packing consists of alternating inorganic bilayers of hexamolybdate and organic bilayers of 1-alkyl-3-methylimidazolium. Each [Mo6O19]2− is sandwiched among the four imidazolium rings in one layer, and connected to the imidazolium heads in neighboring layer through hydrogen bonds. The thermal behaviors of them were studied by differential scanning calorimetry and thermogravimetry. The melting point of three MILs are below 100°C and all of them show good thermal stability. The electrochemical behavior and electrocatalysis of three MILs bulk-modified carbon paste electrodes have been studied by cyclic voltammetry. The modified electrode shows good electrocatalytic activity towards the reduction of bromopropionic acid.