The Beginning of HCN Polymerization: Iminoacetonitrile Formation and Its Implications in Astrochemical Environments
Journal article, 2021

Hydrogen cyanide (HCN) is known to react with complex organic materials and is a key reagent in the formation of various prebiotic building blocks, including amino acids and nucleobases. Here, we explore the possible first step in several such processes, the dimerization of HCN into iminoacetonitrile. Our study combines steered ab initio molecular dynamics and quantum chemistry to evaluate the kinetics and thermodynamics of base-catalyzed dimerization of HCN in the liquid state. Simulations predict a formation mechanism of iminoacetonitrile that is consistent with experimentally observed time scales for HCN polymerization, suggesting that HCN dimerization may be the rate-determining step in the assembly of more complex reaction products. The predicted kinetics permits for iminoacetonitrile formation in a host of astrochemical environments, including on the early Earth, on periodically heated subsurfaces of comets, and following heating events on colder bodies, such as Saturn’s moon Titan.


steered ab initio molecular dynamics



prebiotic chemistry


Hilda Sandström

Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry

Martin Rahm

Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry

ACS Earth and Space Chemistry

24723452 (eISSN)

Vol. 5 8 2152-2159

Subject Categories

Physical Chemistry

Polymer Technologies

Theoretical Chemistry



Related datasets

Theoretical studies of iminoacetonitrile formation [dataset]

URI: DOI: 10.5878/37fw-8a25 ID: 2021-131

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