Reversible Iodine Capture by Nonporous Pillar[6]arene Crystals

Abstract

Here we report that easily obtained per-ethylated pillar[6]arene (EtP6) is a new adsorbent for iodine capture with high chemical and thermal stability. Nonporous EtP6 solids are shown to capture not only volatile iodine in the air but also iodine dissolved in an organic solvent and aqueous solution. Uptake of iodine leads to a structural transformation of EtP6 in the solid state. In the single crystal structure of iodine-doped EtP6 (I@EtP6), each adsorbed iodine molecule is located between two adjacent EtP6 molecules to form a linear supramolecular polymer. Iodine is released spontaneously from I@EtP6 solids when they are immersed in cyclohexane. These EtP6 solids can be reused many times without losing iodine capture capacity.

Applications of Pillar[n]arene‐Based Supramolecular Assemblies

“…: 99 8 8C) is almost the same as that of n-heptane (b.p. Styrene with over 99 %purity could be obtained by exposing the crystals H16 to the 1:1m ixture vapor for 6h and subsequent heating to desorb the styrene encapsulated in the crystals H16.T he same group reported iodine vapor uptake using activated crystals H16 (Figure 12 c), [32] however, no uptake was observed in the presence of the activated pillar [5]arene crystals H14.E ach iodine molecule is located between two distorted H16 molecules.I odine molecules encapsulated in the crystals were released by immersing the host-guest complex crystals in cyclohexane. Selective isooctane vapor uptake from am ixture of isooctane and n-heptane vapors was observed in the presence of activated crystals H16.…”

Metal–Organic Framework Based Microcapsules

“…[34] Developing high-efficiencya dsorbents to capture iodine (I 2 )w ould be au seful routes to overcome these issues.R ecently,s ome functional materials have been designed and synthesized to adsorbing iodine with high capacity through Y···I (Y = N, S, O) halogen bonding [36,37] and charge-transfer interaction between benzene and iodine. [38] Taking account of the structural and elemental advantages of MBM, such as unique bowl-like,h ierarchical porosity and rich N, S, O elements,t he I 2 uptake ability of MBM was investigated. Firstly,M BM were placed under I 2 vapor atmosphere at 100 8 8Cf or 2hto investigate their I 2 vapor sorption capacity.…”

Supramolekulare Pillar[n]aren‐Aggregate und ihre Anwendungen

“…Die gleiche Gruppe beschrieb auch die Aufnahme von Iod-Dämpfen mithilfe der aktivierten H16-Kristalle (Abbildung 12 c). [32] In Gegenwart der aktivierten Pillar [5] [36] Anorganische Tr äger haben im Allgemeinen anionische Ladungen, und durch das Eintauchen des Tr ägers in eine wässrige Lçsung mit kationischen Pillar [5]arenen H7 (Abbildung 14 b) wurden die kationischen Pillar [5]arene H7 über elektrostatische Wechselwirkungen auf der Oberfläche immobilisiert;s ow urde eine positiv geladene Oberfläche erzeugt. Danach wurde der Tr äger in eine wässrige Lçsung des anionischen Pillar [5]arens H11 getaucht, und die anionischen Pillar [5]arene wurden auf der Oberfläche immobilisiert.…”