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.

macrocycles. They have been also employed to modify the surface properties of metal nanoparticles via noncovalent host−guest interactions, [31] covering their applications in drug delivery, [32] highly sensitive sensors, [33] selective catalysis, [34] and so on.In addition to their intensive applications based on their host−guest chemistry, macrocycles have also been used as building blocks to construct solid materials including porous organic polymers (POPs), [35,36] metal-organic frameworks (MOFs), [37][38][39][40][41][42][43] and crystalline organic materials (COMs). [44][45][46][47][48][49][50][51][52][53][54][55][56][57] Particular attention should be paid to COMs, a class of organic materials featuring facile preparation, high crystallinity, structural diversity, chemical stability, solution-processability, etc. [58][59][60][61][62][63][64][65][66][67][68][69][70] Different from MOFs that are composed of both inorganic (metal ions) and organic species (organic ligands) through coordination, COMs refer to a kind of crystalline materials composed of pure organics connected by either covalent or noncovalent bonds. [71][72][73] For COMs connected by noncovalent bonds, the typical materials are organic molecular crystals with intriguing properties such as semiconductor, [53] porosity, [68] etc. Owing to the inefficient packing of organic building blocks in the crystal state, some molecular crystals display extrinsic porosity, which are often termed as hydrogen-bonded organic frameworks (HOFs) [74,75] or supramolecular organic frameworks (SOFs). [76][77][78][79][80] For COMs connected by covalent bonds, typical materials are crystalline covalent organic frameworks (COFs), which were firstly reported in 2005 by Yaghi and co-workers [44] Benefitting from rigid chemical bonds and building blocks, COFs show permanent and well-ordered porosity. [45][46][47][48] Supramolecular-macrocycle-based COMs, a class of COMs with macrocycles as the main building blocks, have drawn particular attention in recent years. According to their components, supramolecular-macrocycle-based COMs can be classified into two main categories, the ones composed of pure macrocycles and the others consisting of macrocycles and other simple organic building blocks. Owing to their prefabricated cavities of a certain type, some of macrocycle-based COMs exhibit intrinsic microporosity for guest adsorption in the solid state. On the other hand, the extrinsic porosity of some macrocyclebased COMs may form due to the inefficient packing of these rigid macrocyclic molecules in the crystalline state. In certain circumstances, both intrinsic and extrinsic microporosity can be created in a single lattice of a certain COM, thus leading to Supramolecular macrocycles are well known as guest receptors in supramolecular chemistry, especially host−guest chemistry. In addition to their wide applications in host−guest chemistry and related areas, macrocycles have also been employed to construct crystalline organic materials (COMs) owing to their particular structur...

The incorporation of supramolecular macrocycles into porous organic polymers may endow the material with enhanced uptake of specific guests through host−guest interactions. Here we report a solvent and catalyst-free mechanochemical synthesis of pillar[5]quinone (P5Q) derived multi-microporous organic polymers with hydrophenazine linkages (MHP-P5Q), which show a unique 3-step N 2 adsorption isotherm. In comparison with analogous microporous hydrophenazine-linked organic polymers (MHPs) obtained using simple twofold benzoquinones, MHP-P5Q is demonstrated to have a superior performance in radioactive iodomethane (CH 3 I) capture and storage. Mechanistic studies show that the rigid pillar[5]arene cavity has additional binding sites though host−guest interactions as well as the halogen bond (−I⋯N = C−) and chemical adsorption in the multi-microporous MHP-P5Q mainly account for the rapid and highcapacity adsorption and long-term storage of CH 3 I.