Evolving complex systems from simple molecules
Abstract
Until very recently, synthetic chemistry has focussed on the creation of chemical
entities with desirable properties through the programmed application of isolated
chemical reactions, either individually or in a cascade that afford a target compound
selectively. By contrast, biological systems operate using a plethora of complex
interconnected signaling and metabolic networks with multiple checkpoint controls
and feedback loops allowing biological systems to adapt and respond rapidly to
external stimuli. Systems chemistry attempts to capture the complexity and emergent
phenomena prevalent in the life sciences within a wholly synthetic chemical
framework. In this approach, complex phenomena are expressed by a group of
synthetic chemical entities designed to interact and react with many partners within
the ensemble in programmed ways. In this manner, it should be possible to create
synthetic chemical systems whose properties are not simply the linear sum of the
attributes of the individual components.
Chapter 1 discusses the role of complex networks in various aspects of chemistry-
related research from the origin of life to nanotechnology. Further, it introduces the
concept of Systems chemistry, giving various examples of dynamic covalent
networks, self-replicating systems and molecular logic gates, showing the
applications of complex system research.
Chapter 2 discusses the components of replicator design. Further, it introduces a
network based on recognition mediated reactions that is implemented by length-
segregation of the substrates and displays properties of self-sorting.
Chapter 3 presents a fully addressable chemical system based on auto- and cross-
catalytic properties of product templates. The system is described by Boolean logic
operations with different template inputs giving different template outputs.
Chapter 4 introduces a dynamic network which fate is determined by a single
recognition event. The replicator is capable of exploiting and dominating the
exchanging pool of reagents in order to amplify its own formation at the expense of
other species through the non-linear kinetics inherent in minimal replication.
Chapter 5 focuses on the development of complex dynamic systems from
structurally simple molecules. The new approach allows creating multicomponent
networks with many reaction pathways operating simultaneously from readily
available substrates.
Type
Thesis, PhD Doctor of Philosophy
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