Computational Astrobiology and Prebiotic Chemistry

What is the molecular basis of life, and how did life originate? These are fundamental questions that ultimately will involve systems of extreme complexity. To help evaluate which initial chemistry might have given rise to such complexity, we are studying one of the Universe’s simplest and most ubiquitous molecules.

Hydrogen cyanide, HCN, is believed to be a key ingredient for prebiotic chemistry, and a versatile building block for the construction of biomolecules. However, the chemical structure of HCN-based polymers remains an open question. There are significant challenges associated with the characterization of polymeric HCN, and highly complex mixtures of soluble and insoluble materials are typically generated in laboratories. 

To tackle this challenge, we are using a combination quantum chemistry and theoretical condensed matter physics methodology to explore well-defined HCN-based materials and polymerization mechanisms. It is possible that such structures might form under kinetic controlled conditions (low temperature) and over long time-scales. To evaluate how HCN chemistry plays into observations we are collaborating with planetary scientists, whose particular focus is Saturn’s moon Titan. Titan can, in some respects, be considered a frozen over version of the early Earth, and the former provides a natural laboratory for studying prebiotic chemistry occurring under cryogenic conditions. One of the most abundant products of Titan’s atmospheric chemistry is HCN, where it contributes to the formation of not yet well-understood photochemical hazes.’

Polyimine, a possible result of HCN polymerization in the outer solar system. Predicted structure shown together with radar imaging of hydrocarbon lakes on Titan.

Research Highlights: