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

Abstract The design of a rare combination of interpenetrated and catenated 3D+2D→3D MOF {[Cd ₄ (dim) ₄ (dht) ₄ (H ₂ O) 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 NH ₃ , 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′@NH ₃ and 1′@HCl . 1′@NH ₃ 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.