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A series of valine functionalized supramolecular hypervalent iodine macrocycles (HIMs) with enlarged aromatic cores, including naphthalene and anthraquinone, have been synthesized. Single crystal analysis shows the macrocycles consist of a slightly distorted cyclic planner interior with three carbonyl oxygens from the amino acid residues facing towards the center of the macrocycle and all three alkyl groups above one plane. Owing to the enlarged aromatic core, the naphthalene-based HIMs were successfully co-crystallized with Buckminsterfullerene (C60) into a long-range columnar supramolecular structure. The assembled architecture displays a long-range pattern between HIM and C60 in a 2 : 3 ratio, respectively. Disassembly of the HIMs can be accomplished by adding anions of tetrabutylammonium (TBA) salts that selectively bind with the electron deficient iodine center in HIM systems. A comparative study of the associations constants and the binding energies for different aromatic-based HIMs with TBA(Cl) and TBA(Br) is presented. 

This study explores the dynamic self-assembly and disassembly of hypervalent iodine-based macrocycles (HIMs) guided by secondary bonding interactions. The reversible disassembly and reassembly of HIMs are facilitated through anion binding via the addition of tetrabutylammonium (TBA) salts or removal of the anion by the addition of silver nitrate. The association constants for HIM monomers with TBA(Cl) and TBA(Br) are calculated and show a correlation with the strength of the iodine–anion bond. A unique tetracoordinate hypervalent iodine-based compound was identified as the disassembled monomer. Last, the study reveals the dynamic bonding nature of these macrocycles in solution, allowing for rearrangement and participation in dynamic bonding chemistry. 

We synthesized single crystals for Mn2-xZnxSb (0 ≤ x ≤ 1) and studied their magnetic and electronic transport properties. This material system displays rich magnetic phase tunable with temperature and Zn composition. In addition, two groups of distinct magnetic and electronic properties, separated by a critical Zn composition of x = 0.6, are discovered. The Zn-less samples are metallic and characterized by a resistivity jump at the magnetic ordering temperature, while the Zn-rich samples lose metallicity and show a metal-to-insulator transition-like feature tunable by magnetic field. Our findings establish Mn2-xZnxSb as a promising material platform that offers opportunities to study how the coupling of spin, charge, and lattice degrees of freedom governs interesting transport properties in 2D magnets, which is currently a topic of broad interest. 

Abstract This Assessment Update by the Environmental Effects Assessment Panel (EEAP) of the United Nations Environment Programme (UNEP) considers the interactive effects of solar UV radiation, global warming, and other weathering factors on plastics. The Assessment illustrates the significance of solar UV radiation in decreasing the durability of plastic materials, degradation of plastic debris, formation of micro- and nanoplastic particles and accompanying leaching of potential toxic compounds. Micro- and nanoplastics have been found in all ecosystems, the atmosphere, and in humans. While the potential biological risks are not yet well-established, the widespread and increasing occurrence of plastic pollution is reason for continuing research and monitoring. Plastic debris persists after its intended life in soils, water bodies and the atmosphere as well as in living organisms. To counteract accumulation of plastics in the environment, the lifetime of novel plastics or plastic alternatives should better match the functional life of products, with eventual breakdown releasing harmless substances to the environment.