Face‐Capped M 4 L 4 Tetrahedral Metal–Organic Cage: Iodine Capture and Release, Ion Exchange, and Electrical Conductivity

An M 4 L 4 type metal–organic cage (MOC‐19) has been synthesized from the one‐pot reaction of tri(pyridinylmethylene)phenylbenzeneamine (TPBA) with hydrated Zn(ClO 4 ) 2 under mild conditions and characterized by single‐crystal X‐Ray diffraction. Iodine capture studies show that the porous crystals of MOC‐19 exhibit a versatile behavior to accumulate iodine species not only in vapor (for I 2 ) but also in solution (for I 2 and I 3 − ), and anion‐exchange experiments indicate the capacity to extract IO 3 − anions from aqueous solution. Enrichment of iodine species from KI/I 2 aqueous solution proceeds facilely, revealing a pseudo‐second‐order kinetics of I 3 − adsorption. Furthermore, the electrical conductivity of MOC‐19 single crystals could be significantly altered by I 2 inclusion.