Metallo‐Supramolecular Block Copolymers

Abstract

Supramolecular copolymers have become of increasing interest in recent years for the search of new materials with tunable properties. In particular, metallo‐supramolecular block copolymers—copolymers in which the blocks are linked together by a metal–ligand complex—have seen important progresses, allowing better control over the synthetic strategies for various architectures, and providing a better understanding of the parameters governing their self‐assembly. We review here recent developments on the synthesis and self‐assembly of such materials achieved in this field.

Supramolekulare Blockcopolymere mit Cucurbit[8]uril in Wasser

“…[5][6][7][8][9] Metall-Ligand-Bindungen können auch für die Herstellung von Blockcopolymeren genutzt werden, die selbst in wässrigen Lösungen stabil sind. [10][11][12][13] In diesen Fällen gehen allerdings die für reversible Bindungen typischen dynamischen Eigenschaften weitgehend verloren, und das Vorhandensein von Metallen kann außerdem eine Anwendung in biologischen Systemen einschränken. Durch gezielten Entwurf von multiplen, linear ausgerichteten Wasserstoffbrücken konnten hohe Bindungskonstanten in organischen Lösungsmitteln erzielt werden; [4,[14][15][16][17][18] diese Strategie ließ sich bislang jedoch nicht auf wässrige Lösungen ausweiten, da Wassermoleküle um die Bindungsstellen für Wasserstoffbrücken konkurrieren.…”

Using Metallo‐Supramolecular Block Copolymers for the Synthesis of Higher Order Nanostructured Assemblies

“…The key features of these metallo-polymer systems include their specificity, directionality, and opportunity to exploit the tuneable binding strength and reversibility of the metal-ligand interaction ( Figure 1). [29,37] Linear metallo-supramolecular di-and tri-block copolymers with symmetrical or asymmetrical metal-ligand interactions, i.e., either having the same or different ligands bound to one metal center, have been intensively studied in the past decade in particular. This is perhaps owing to their facile and versatile synthesis, similarity to conventional copolymers, and great promise for self-assembly into interesting and useful architectures.…”

“…For a more comprehensive background on main chain metallo-supramolecular polymers, the reader is directed toward several excellent reviews on the subject. [29][30]37] Furthermore, in this highlight we will only cover metallo-supramolecular polymers containing one metal-ligand complex which serves as a linkage between homo-and copolymers and therefore we will not be covering literature on multiple complex containing metallo-polymers in detail, or the broader topic of metal containing polymers. Once more, the reader is directed toward several excellent and comprehensive reviews on these topics.…”

“…[19,38] Block copolymers which are formed via a supramolecular transition metal complex linkage between the homopolymer segments have shown particular research interest. [27,29,36] This is perhaps owing to their ability to undergo conventional self-assembly into various morphologies, as for covalent block copolymers, yet still retain supramolecular reversibility and the unique properties of transition metal complexes, thus offering many advantages over conventionally synthesized architectures. [39][40][41][42][43][44] Moreover, in recent years, researchers have begun to pre-design and manipulate such metallo-supramolecular block copolymers to target specific nanostructures whereby a key design feature in their synthesis is utilized after self-assembly has occurred; viz, the supramolecular linkage can be selectively cleaved to remove the attached polymer blocks, thus producing novel functional architectures from tailor made parent self-assembled structures.…”

Nonlinear mechanics of thermoreversibly associating dendrimer glasses

“…[1][2][3][4][5][6] Examples of thermoreversible bonds include π-π-stacking, [7][8][9][10] hydrogen bonding, [11][12][13][14][15] and metal ligand bonding. [16][17][18][19][20][21][22][23][24][25] In associating polymer systems (APs), the presence of thermoreversible bonds leads to exquisitely tunable rheological properties, particularly when the product˙ τ sb of the strain rate˙ and sticky bond lifetime τ sb is of order unity. [18,[26][27][28] AP networks are also capable of dramatic "self-healing" under a variety of conditions, e.g., after fracture.…”