A solvent- and pH-stable NiII-based metal-organic framework with benzothiadiazole derivative for proton conduction

A one-dimensional metal–organic framework (MOF) with the formula of {[Ni(BIBT)(pydc)(H2O)2]·H2O}n (JXUST-26, BIBT = 4,7-bis(1H-imidazole-1-yl)-2,1,3-benzothiadiazole, H2pydc = 3,5-pyridinedicarboxylic acid) has been successfully synthesized under solvothermal condition, which crystallizes in the monoclinic C2/c space group. It is noteworthy that JXUST-26 exhibits good solvents and pH stabilities as well as relatively good thermal stability. The proton conductivity increases with increasing temperature, and reaches 1.65 × 10−8 S·cm−1 at 30°C and 3.24 × 10−7 S·cm−1 at 80°C under 98% relative humidity, respectively. In the low temperature range of 313–353 K, the activating energy (Ea) is 0.51 eV, which belongs to the Vehicle mechanism.