Different Modes of Anion Response Cause Circulatory Phase Transfer of a Coordination Cage with Controlled Directionality

Surface chemistry of metal-organic polyhedra

Metal-organic polyhedra (MOPs) are discrete, intrinsically-porous architectures that operate at the molecular regime and, owing to peripheral reactive sites, exhibit rich surface chemistry. Researchers have recently exploited this reactivity through post-synthetic modification (PSM) to generate specialised molecular platforms that may overcome certain limitations of extended porous materials. Indeed, the combination of modular solubility, orthogonal reactive sites, and accessible cavities yields a highly versatile molecular platform for solution to solid-state applications. In this feature article, we discuss representative examples of the PSM chemistry of MOPs, from proof-of-concept studies to practical applications, and highlight future directions for the MOP field.

Synthesis of Highly Functionalizable Symmetrically and Unsymmetrically Substituted Triarylboranes from Bench-Stable Boron Precursors

A novel and convenient methodology for the one-pot synthesis of sterically congested triarylboranes by using bench-stable aryltrifluoroborates as the boron source is reported. This procedure gives systematic access to symmetrically and unsymmetrically substituted triarylboranes of the types BAr2 Ar' and BArAr'Ar'', respectively. Three unsymmetrically substituted triarylboranes as well as their iridium-catalyzed C-H borylation products are reported. These borylated triarylboranes contain one to three positions that can subsequently be orthogonally functionalized in follow-up reactions, such as Suzuki-Miyaura cross-couplings or Sonogashira couplings.

Functional Material Systems Based on Soft Cages

Discrete molecular soft cages integrate multiple functionalities in one molecule. They express their functions from the confined space in their cavity, functional groups in the cavity interior wall and exterior wall, and the chelating nodes in many chelating cages. Such functional integrity render cage molecules special applications in material engineering. Increasing applications of cage molecules in material design have been reported in recent years. Compared with other cavity-rich molecular structures such as metal-organic framework (MOF) or covalent organic frameworks (COF), discrete soft cages present the unique advantage of material design flexibility, that they can easily composite with nanoparticles or polymers and exist in materials of various forms. We document the development of cage-based materials in recent years and expect to further inspire materials engineering to integrate contribution from the functionality specificity of cage molecules and ultimately promote the development of functional materials and thus human life qualities.

Heat Engine Drives Transport of an FeII 4 L4 Cage and Cargo

The directed motion of species against a chemical potential gradient is a fundamental feature of living systems, underpinning processes that range from transport through cell membranes to neurotransmission. The development of artificial active cargo transport could enable new modes of chemical purification and pumping. Here, a heat engine is described that drives chemical cargo between liquid phases to generate a concentration gradient. The heat engine, composed of a functionalized Fe^II ₄ L₄ coordination cage, is grafted with oligoethylene glycol imidazolium chains. These chains undergo a conformational change upon heating, causing the cage and its cargo to reversibly transfer between aqueous and organic phases. Furthermore, sectional heating and cooling allow for the cage to traverse multiple phase boundaries, allowing for longer-distance transport than would be possible using a single pair of phases.