Overcoming Limited Selection in Multicyclic Replication Networks

Background — The development and deployment of replicating molecular networks can potentially revolutionize materials fabrication at the nanometre scale. Molecular replication can deliver synthetic machinery that is capable of directing its own synthesis and co-operating with other similar systems to create an organized hierarchy. Within this broad objective, the development of efficient protocols that allow replication, organization and emergent behaviour is required. This approach to predetermined dynamic behaviour has been termed “systems chemistry”. We have developed a series of molecular networks that are capable of replication by a variety of different mechanisms. The ability of these individual replicating systems to function as building blocks within more complex reaction networks is related to their ability to selectively bind reagents and accelerate the reactions between them. Kinetic selection based on the autocatalytic or cross-catalytic efficiencies of instruction templates is, however, unlikely to be enough to achieve the goals set out above.
Dynamic covalent chemistry offers an opportunity to develop synthetic protocols that incorporate a degree of error checking through the dynamic and reversible association of the components of a target structure through covalent bonds. The limited number of organic reactions that form covalent bonds and that are also completely reversible under mild conditions hampers the development of this field. The coupling of dynamic covalent reaction networks to replication processes offers an attractive route into reconfigurable reaction systems that are capable of responding to instructional templates.

Project — In this project, we will attempt to demonstrate that the ability of a chemical system to select and amplify one species from a mixture within closed reactor is fundamentally limited. This limitation exists for approaches that exploit only thermodynamic selection and also for those that incorporate irreversible processes within a dynamic , reaction network. In order to overcome this barrier, we will develop systems that are capable of exploiting propagating chemical waves (Figure 1 – mediated by replicating organic structures – as selection tools.