Hydrogen-Bonded Duplexes with Lengthened Linkers

Abstract

Connecting basic hydrogen-bonding units with lengthened flexible or rigid linkers generates oligoamide strands that carry new H-bonding sequences and association specificity, leading to H-bonded homo- and heteroduplexes with association constants in the 10 M range in chloroform. Computational and experimental studies indicate that in duplexes with rigid aromatic linkers the oligoamide strands adopt bent conformations that allow the formation of interstrand H-bonds and accommodate the introduced aromatic liners, offering a new series of association units.

The Diverse World of Foldamers: Endless Possibilities of Self-Assembly

“…The exceptional stability, further confirmed by isothermal titration microcalorimetry and thin-layer chromatography (TLC), was explained by positive cooperativity among the numerous hydrogen bonding and van der Waals interactions, as well as the preorganization of individual strands by intramolecular hydrogen bonds. In addition, when the hydrogen bonding units were connected with lengthened flexible linkers, the association constant decreased, while using rigid aromatic linkers led to pairings with comparable stability, because the bent conformation was counterbalanced by the π-stacking between the linkers themselves [ 199 ]. A quadruply H-bonded duplex was further employed as an inducer for the formation of an antiparallel β-sheet between two tripeptides that were bonded at the C- and N-termini, respectively.…”

“… ( a ) Quadruply and ( b ) sixtuply intermolecularly hydrogen bonded dimers (Refs. [ 196 , 197 , 198 , 199 , 200 ]); ( c ) Heteroduplex and ( d ) homoduplex of foldamers whose linear strands are not complementary (Ref. [ 201 ]); ( e ) An example of self-recognizing β-sheets based on the Orn( i -PrCO-Hao) sequence, highlighted in red (Refs.…”

The influence of substituents on gelation and stacking order of oligoaramid – based supramolecular networks

“…Oligomers or polymers from these monomeric units have the ability to interact via hydrogen bonding between their amide bonds or p-p stacking between the aromatic rings. 11 These interactions are a prerequisite for the formation of supramolecular structures. However, rigid molecules often suffer from low solubility, limiting their otherwise promising utilization for materials with intriguing properties.…”

Synthesis and properties of poly(norbornene)s with lateral aramid groups

“…These comb-like polymers were prepared via ring-opening metathesis polymerization (ROMP). Aramids are good candidates to undergo different supramolecular interactions, such as hydrogen bonds 14 and aromatic stacking 15,16 In order to investigate the distinct influence of either one of these intermolecular forces, we synthesized two types of monomers containing different rigid rod-like components. One monomer possesses a rod consisting of an aramid trimer able to interact primarily via hydrogen bonds.…”