Abstract

s-Triazine-Based Self-Assembling Information Molecules

Nature stores biological information in form of a four-letter alphabet within the polymeric chain of DNA. Here, we have designed a series of triazine-based oligomers equipped with hydrogen bond acceptor (A)
 and donor (D) sites, which should lead to duplex assembly and template-directed synthesis, i.e. synthetic analogues of DNA. The oligomers are composed of four components: a recognition-based pairing system, backbone, linker and solubility controlling moieties. The oligomers were synthesised using the selective reactivity of trichlorotriazine. Two generations of s-triazine-based homo-sequence oligomers bearing either hydrogen-bond donor or hydrogen-bond acceptor recognition units were synthesised, and their assembly properties were studied via NMR titration experiments. The value of the association constant for the first generation homo-sequence dimers was within the range expected for a single hydrogen bond. This suggests that, in the solution state, these systems form aggregates rather than canonical duplex structures. However, the second generation of length-complementary homo-sequence dimers and trimers demonstrated the desired duplex formation. Therefore, these synthetically accessible systems are promising prototypes for stable information molecules, with the potential to encode and replicate chemical information in the same way as DNA. As the first step towards the synthesis of mixed-sequence information oligomers, an s-triazine based hetero-sequence dimer was synthesised, and the competing equilibrium between folding and duplex assembly was investigated. Strategies for the formation of branched-chain macromolecules with up to nine recognition modules were explored by attaching the second-generation homo-sequence trimers to an s-triazine core.

Karine Hakobyan