Organically templated metal sulfate-oxalates: Solvent-free synthesis, crystal structure, and proton conduction

Abstract

Two new metal sulfate-oxalates, namely, (H4bapp)0.5·VO(SO4)(C2O4) (SCU-11) and H2depa⋅Mn2(SO4)(C2O4)2(H2O)⋅H2O (SCU-13), were prepared under solvent-free conditions, where bapp = 1,4-bis(3-aminopropyl)piperazine and depa = 3-(diethylamino)propylamine. SCU-11 has a chainlike structure containing pendant SO4 groups. SCU-13 has a three-dimensional open-framework structure with chainlike manganese oxalate chains assembled by SO4 groups. Notably, SCU-11 shows excellent water stability and a high proton conductivity of 1.2 × 10−3 S cm−1 at 25 °C under 98% relative humidity. The magnetic susceptibility data for the two compounds were also reported.