Ions Conduction in pH Stable Interpenetrated‐Catenated Metal‐Organic Framework

The design of a rare combination of interpenetrated and catenated 3D+2D→3D MOF {[Cd4(dim)4(dht)4(H2O)4](Sol)x}n (1), with a unique network and extreme pH stability, has been developed for exceptional ionic conduction across a wide range of temperature and humidity conditions. The bare pore derivative of 1 (1') features remarkable structural flexibility and large pores accessible to encapsulate molecules such as NH3, HCl, and KOH, enabling it to function as an efficient conductor for both proton and hydroxide ions. 1' demonstrates substantial thermal-influenced proton conductivity of 4.6 × 10-3 S cm-1 at 80°C and 95% RH, which is significantly enhanced by the encapsulation of guest molecules, 1'@NH3 and 1'@HCl. 1'@NH3 exhibits a proton conductivity of 3 × 10-2 S cm-1 at 80°C and 95%RH, while the highly polar 1'@HCl achieves 1.21 S cm-1 . The 30°C (room temperature) proton conductivity of 1'@HCl is highly remarkable, reaching 6.8 × 10-1 S cm-1 at 95%RH, representing one of the highest values reported for MOFs to date. Similarly, 1'@KOH exhibits hydroxide ion conduction, rising from 2.8 × 10-1 S cm-1 at 25°C to 7.6 × 10-1 S cm-1 at 80°C in 95%RH, further establishing its performance as one of the highest reported so far.