Synthesis and structure of a proton-conductive supramolecular complex based on poly-Keggin-anion chains

► Heteropolyacids have suitable characteristics to be used proton conductors with excellent proton conductivity. ► A new proton-conductive supramolecular complex based-on [PW12O40]3− and isonicotinic acid N-oxide was constructed. ► Incorporation of salts into the self-ordered hydrogen-bonded networks was determined by using single-crystal structure. ► The complex is insoluble in water and showed good proton conductivities of 10−3 S cm−1 in the temperature range of 85-100 °C. ► The complex offers a new example in the field of solid state proton conductors by increasing the stability and conductivity.