Emergent supramolecular assembly properties of a recognition-encoded oligoester

Abstract

The sequences of oligomeric molecules equipped with interacting side-chains encode the threedimensional structure, the supramolecular assembly properties, and ultimately function. In an attempt to replicate the duplex forming properties of nucleic acids, an oligoester containing an alternating sequence of hydrogen bonding donor (D) and acceptor (A) residues was synthesised. Characterisation of assembly properties of the ADAD oligomer revealed a supramolecular architecture that resembles the kissing stem-loops motif found in folded RNA. NMR dilution and melting experiments in chloroform and 1,1,2,2-tetrachloroethane show that intramolecular hydrogen bonding interactions between the terminal phenol and phosphine oxide recognition sites in the ADAD 4-mer lead to 1,4-folding. This folded stemloop structure can be denatured to give the single strand by heating. At higher concentrations or lower temperatures, the stem-loop dimerises via intermolecular hydrogen bonding interactions between the two inner recognition sites, leading to a kissing stem-loops structure. The results suggest a rich supramolecular chemistry for these recognition-encoded oligoesters and lay strong foundations for the future development of new functional materials based on synthetic information molecules.

High-Fidelity Sequence-Selective Duplex Formation by Recognition-Encoded Melamine Oligomers

“… 12 The synthesis of oligomers that form duplexes has turned out to be a tractable problem, 13 − 46 and we have found that some of these compounds also fold and catalyze reactions in a manner reminiscent of nascent RNA function. 47 , 48 …”

Folding and duplex formation in mixed sequence recognition-encodedm-phenylene ethynylene polymers

“…[13][14][15][16][17][18][19][20] Some of these synthetic systems also exhibit properties that resemble those found in biopolymers, such as substrate binding, self-assembly and catalysis. [21][22][23][24][25][26][27] One of the most important functional properties found in biomolecules is the ability of nucleic acid oligomers to template the synthesis of a specic sequence of another oligomer, either protein or nucleic acid. This process is the molecular basis of evolution and is directly related to the duplex structure formed by nucleic acids.…”

Single-Site Binding of Pyrene to Poly(ester-Imide)s Incorporating Long Spacer Units: Prediction of NMR Resonance-Patterns from a Fractal Model

“…4,5 Indeed, some very significant progress in devising a synthetic "information chemistry" has been made in recent years, notably with the development of sequence-specific polymerisation (i.e. sequence-writing) methodologies and mass-spectrometric sequencing techniques, [6][7][8] information-transfer protocols, [9][10][11] and the use of small "reader-molecules" to recognise and report copolymer sequence-information. [12][13][14][15] Using the latter technique, we recently showed that highly sequence-dependent 1 H NMR complexation shifts are produced in the spectra of copolyimides based on 1,4,5,8-naphthalene tetracarboxylic diimide (NDI) on complexation of an aromatic "probe" molecule such as pyrene or perylene.…”