A Diverse Array of Large Capsules Transform in Response to Stimuli

Abstract

The allosteric regulation of biomolecules, such as enzymes, enables them to adapt and alter their conformation to fit specific substrates, expressing different functionalities in response to stimuli. Different stimuli can also trigger synthetic coordination cages to change their shape, size, and nuclearity by reconfiguring the dynamic metal−ligand bonds that hold them together. Here we demonstrate an abiological system consisting of different organic subcomponents and Zn II metal ions, which can respond to simple stimuli in complex ways. A Zn II 20 L 12 dodecahedron transforms to give a larger Zn II 30 L 12 icosidodecahedron through subcomponent exchange, as an aldehyde that forms bidentate ligands is displaced in favor of one that forms tridentate ligands together with a pentaamine subcomponent. In the presence of a chiral template guest, the same system that produced the icosidodecahedron instead gives a Zn II 15 L 6 truncated rhombohedral architecture through enantioselective self-assembly. Under specific crystallization conditions, a guest induces a further reconfiguration of either the Zn II 30 L 12 or Zn II 15 L 6 cages to yield an unprecedented Zn II 20 L 8 pseudo-truncated octahedral structure. The transformation network of these cages shows how large synthetic hosts can undergo structural adaptation through the application of chemical stimuli, opening pathways to broader applications.

Ion Mobility Mass Spectrometry for Large Synthetic Molecules: Expanding the Analytical Toolbox

“…This is of particular interest when screening the products of self-assembly reactions, where multiple stoichiometries, structures and conformations are present. In their pioneering works, Wesdemiotis, Newkome and co-workers demonstrated this for metallosupramolecular complexes, − and since then many groups with similar synthetic targets, such as Chan, − Clever, − Li, − and Nitschke, − have deployed IM-MS as a standard analytical technique.…”

Ion Mobility Mass Spectrometry for Synthetic Molecules: Expanding the Analytical Toolbox

“…License: CC BY-NC-ND 4.0 is of particular interest when screening the products of self-assembly reactions, where multiple stoichiometries, structures and conformations are present simultaneously. In their pioneering works, Wesdemiotis, Newkome and co-workers demonstrated this for metallosupramolecular complexes [71][72][73][74] and since then many groups with similar synthetic targets, such as Chan, [75][76][77][78] Clever, [79][80][81][82][83] Li, [84][85][86][87][88][89][90] and Nitschke, [91][92][93][94] have deployed IM-MS as a standard analytical technique.…”

Stabilization of Lantern‐Type Metal‐Organic Cages (MOCs) by Protective Control of Ligand Exchange Rates

“…Typically charged, square planar palladium-based lantern-type cages and octahedral cobalt/iron/zinc-based tetrahedral, octahedral, and cubic MOCs rely on non-chromatographic techniques to determine speciation. [9] NMR spectroscopy, mass spectrometry, and UV-vis spectroscopy of complex mixtures of species can be difficult to obtain, decipher, and quantify accurately.…”