Superprotonic conduction through one-dimensional ordered alkali metal ion chains in a lanthanide-organic framework

Although no evident hydrogen-bond network appears, an ultrahigh proton conductivity of 2.91 × 10 −2 S cm −1 at 363 K and 90% RH with an ultralow activation energy of 0.10 eV was observed in an anionic lanthanide-organic framework Na 2 [Eu(SDB) 2 (COO)]·0.375DMF·0.4H 2 O (1); both values approach the records among all reported proton-conducting MOF materials. This suggests that the proton conduction process in 1 is reminiscent of the Grotthuss mechanism, which together reveals an effective proton transportation pathway associated with aligned Na + and their coordinated water. An ultrahigh proton conductivity of 2.91 × 10 −2 S cm −1 and an ultralow activation energy of 0.10 eV were observed in an anionic lanthanide-organic framework. Both values approach the records for proton-conducting MOF materials.