Combination of orthogonal supramolecular interactions in polymeric architectures

Abstract

Supramolecular polymers represent a highly interesting approach towards new "smart materials". A recent strategy includes the combination of different "orthogonal" non-covalent binding sites within one polymer system. Different functionalities can be introduced in a highly defined way by controlled self-assembly processes. This feature article presents highlights in the supramolecular polymer chemistry of multiple hydrogen-bonding, metal complexation (especially of bi- and terpyridines) and host-guest interactions as well as recent advances in combining these interactions in novel polymers.

Hierarchical Self‐Assembly of One‐Dimensional Streptavidin Bundles as a Collagen Mimetic for the Biomineralization of Calcite

“…[42,43] For this proof-ofprinciple study, we selected a preorganized bis-biotinylated terpyridine ligand Biot 2 -terpy that binds to two cis-related sites in streptavidin. [44][45][46][47] A ferrous ion was chosen as terpyridine binds in a cooperative fashion (K 1 = 1.26 10 7 m À1 , K 2 = 6.31 10 13 m À1 ), [48] thus ensuring the exclusive formation of a linear connector bearing four biotin anchors ( Figure 2). Experimental details for the synthesis and the characterization of the [Fe(Biot 2 -terpy) 2 ] 2+ complex are described in the Supporting Information.…”

Supramolecular Polymers Constructed through Self-sorting Host–Guest Interactions

“…19 For instance, over the past several years, a huge number of reports on the construction of crosslinked polymers and supramolecular polymers connected by cucurbit[n]urils (especially CB [8]) driven by host-enhanced ππ interaction have been reported by Zhang,20 Scherman, 21 and others. 22 As with the self-sorting studies of CBs, Isaacs and co-workers reported studies on the systematic binding abilities of three members of the CB[n] family (CB[6], CB [7], and CB [8]) toward up to 24 different guests with different structural natures such as size and shape. It was found that the high selectivity between the host and guest molecules would allow for the construction of complex selfsorting systems.…”

“…Thus, some multicomponent supramolecular polymers have been efficiently prepared through this strategy, which displayed tailored chemical and physical properties. Surprisingly, although Schubert et al 7 and Wang et al 8 have presented excellent reviews on the advanced supramolecular polymers constructed from multiple components, the development of supramolecular polymers based on self-sorting hostguest interactions has not been reviewed yet. In this review article, we summarize the recent progress in the construction of supramolecular polymers driven by self-sorting hostguest interactions.…”

“…24 In their primary binding ability studies, they found that both of the guests p-phenylene (Phen) and naphthalene (Naph) could complex with the macrocyclic host CB [7] and CB [8]. However, when mixing CB [7], CB [8], Phen, and Naph together, the Phen moiety only complexed with CB [7] because of the remarkable binding constant (K a = 10 9 M ¹1 ), thus promoting the naphthalene (Naph) moiety to bind with CB [8] to form a 2:1 complex. On the basis of these results, they designed a new monomer 18 (Naph-Phen-Naph) consisting of both Phen and Naph moieties.…”

Hierarchical Self‐Assembly of One‐Dimensional Streptavidin Bundles as a Collagen Mimetic for the Biomineralization of Calcite

“…[42,43] For this proof-ofprinciple study, we selected a preorganized bis-biotinylated terpyridine ligand Biot 2 -terpy that binds to two cis-related sites in streptavidin. [44][45][46][47] A ferrous ion was chosen as terpyridine binds in a cooperative fashion (K 1 = 1.26 10 7 m À1 , K 2 = 6.31 10 13 m À1 ), [48] thus ensuring the exclusive formation of a linear connector bearing four biotin anchors ( Figure 2 2+ ion and Sav can be conveniently monitored with the disappearance of an induced CD signal, l max = 505 nm, caused by the displacement of 2-(4'-hydroxyazobenzene)benzoic acid (HABA, a hydrophobic dye weakly bound within the biotin-binding pocket) by the [Fe(Biot 2 -terpy) 2 ] 2+ ion (see the Supporting Information). [37,49] Upon standing at room temperature, the dilute purple solution containing the metal + ligand + protein triad slowly becomes turbid, suggesting the formation of polymeric material {[Fe(Biot 2 -terpy) 2 ] 2+ &Sav} 1 .…”