Title: From life-inspired materials to the origin of life: oscillators, waves, and patterns by molecular design

Abstract

Living matter functions conceptually differently from non-living matter. It is active and is organized in space and time through the interaction of five major types of processes: biochemical reactions,1 diffusion,2, 3 noncovalent self-assembly, phase separation,4 and mechanical motion. This design provides adaptivity, evolvability, and the ability to self-replicate, which are unique for life. In contrast, the chemists’ ability to build dynamically organized systems (e.g., chemical oscillators) is limited. Interconnections and feedback loops between different processes make them non-modular (holistic) and, consequently, hard to understand and rationally construct. Nevertheless, the ability to construct dynamically organized systems opens possibilities (i) to obtain materials with life-like properties and (ii) to probe the role of dynamic self-assembly in the origin of Life.

In this talk, I propose using the chemists’ ability to design and synthesize molecules for the rational construction of dynamic systems and materials. By designing molecules, we can control (i) the reactions in which they will participate, (ii) the rates of these reactions, (iii) the diffusion coefficients of these molecules, and (iv) noncovalent interactions that are responsible for the self-assembly and phase separation behaviors of these molecules. Therefore, we should be able to control the necessary processes and interactions, and, consequently, the dynamic structures emerging from these interactions.

I will illustrate this strategy with the rational design of chemical oscillators,5 waves,6 patterns, and microstructures.7 We designed thioesters, thiouronium salts, organic disulfides, azocarboxamides, derivatives of maleimide, and other reactants in such a way that their reactions form both positive and negative feedback loops. When we reacted these compounds in a continuously stirred tank reactor or used unstirred pseudo 1D or 2D hydrogel reactors, we obtained chemical oscillators, waves, and patterns correspondingly. By controlling charge-charge interactions, we achieved the autocatalytic formation of complex microcompartments. Moreover, our studies of interactions of HCN with organic thiols showed that these reactions proceed through complex autocatalytic reaction networks leading to a library of heterocycles and amphiphiles that separate into catalytically active liquid compartments. In perspective, this work opens a path toward constructing life-like dynamic materials and observing emergent phenomena in prebiotically relevant chemistry.