Self‐Assembly of Supramolecular Architectures and Polymers by Orthogonal Metal Complexation and Hydrogen‐Bonding Motifs

Abstract

A modular construction kit with two orthogonal noncovalent binding sites for self-assembly of supramolecular architectures is presented. The heteroditopic building blocks contain a terpyridine (tpy) unit for coordination of metal ions and a Hamilton receptor for multiple H-bonding of cyanuric acid derivatives. The association constants of ligand binding of M(II) complexes (M=Ru, Zn, Fe, and Pt) with a dendritic end cap were determined to be in the range of 10(2) and 10(4) L mol(-1) in chloroform. The capabilities for binding of metal ions were investigated by (1)H NMR and UV/Vis spectroscopy. The Fe complexes are most appropriate for the generation of discrete and high-ordered architectures due to their strong tendency to form FeL(2) complexes. Superstructures are readily formed in a one-pot procedure at room temperature. No mutual interactions between the orthogonal binding motifs were observed, and this demonstrates the highly specific nature of each binding process. Decomplexation experiments were carried out to examine the reversibility of Fe-tpy coordination. Substitution of the terminal end cap with a homoditopic bis-cyanurate linkage leads to formation of an iron-containing supramolecular strand. Formation of coordination polymers was confirmed by viscosity measurements. The supramolecular polymer strands can be reversibly cleaved by addition of a terminating cyanuric acid building block, and this proves the dynamic nature of this noncovalent polymerization process.

Controlling supramolecular polymerization through multicomponent self‐assembly

“…Strategies to control the size and shape of nano-and micrometer size objects that rely on selective solvent techniques in the self-assembly of block copolymers will not be discussed here. [60][61][62][63][64][65][66][67][68][69][70][71][72][73] Supramolecular multicomponent gels, [74][75][76][77][78][79][80][81][82][83][84][85][86][87][88][89] or orthogonal self-assembly, [90][91][92][93][94][95][96][97] self-sorting [98][99][100][101][102][103][104] and chiral amplification strategies 105 in multicomponent supramolecular polymers will not be covered in detail, and the interested reader is referred to the recent literature and review articles.…”

Hydrogen-Bonded Supramolecular Polymers

“…Monomer 20 is a heteroditopic building block with a terpyridine moiety and a Hamilton receptor at two ends of a hexanamido spacer, while monomer 21 is a homoditopic cyanurate derivative [39]. The supramolecular polymer 22 can be obtained when a 2:1 mixture of 20 and 21 in chloroform is titrated with 1.0 equiv.…”

“…Reproduced from Ref. [39] by permission of John Wiley & Sons Ltd from 24 was initially obtained followed by polymerization upon addition of 23. The disassembly/assembly of supramolecular polymers could be reversibly switched by addition/removal of K + without interfering with UPy dimerization due to the stronger binding of K + with B21C7 moiety than dialkylammonium moiety.…”

Supramolecular Architectures Incorporating Hydrogen‐Bonding Barbiturate Receptors

“…As metal binding greatly diminished this binding, here the Zn 2+ ions may be described as negative allosteric co‐factors, in analogy with biochemical systems 12. The range of metal‐ion effectors was subsequently extended to include iron, platinum and ruthenium 11b…”