Complete Computational Exploration of Eight-Carbon Hydrocarbon Chemical Space

Area of Science:

• Computational Chemistry
• Organic Chemistry
• Materials Science

Background:

• Hydrocarbons are fundamental chemical compounds.
• The chemical space of hydrocarbons with 8 carbons or less remains underexplored.
• Understanding novel hydrocarbon structures is key for new applications.

Purpose of the Study:

• To exhaustively enumerate and computationally explore the chemical space of hydrocarbons with 8 carbons or less.
• To develop a database (CHX8) of stable molecules and assess their synthesizability.
• To investigate the accessibility of strained, unsaturated, and anti-Bredt ring systems.

Main Methods:

• Density functional theory (DFT) for geometry optimization and energy calculations.
• Identification of all stable molecular structures within the defined chemical space.
• Assignment of a universal strain value as a proxy for synthesizability.

Main Results:

• A comprehensive database, CHX8, containing all stable hydrocarbons with 8 carbons or less was generated.
• A universal strain metric was developed, guiding the synthetic plausibility of molecules.
• Contrary to expectations, most unconventional structures, including strained and anti-Bredt systems, exhibit low relative strain energies, comparable to or less than cubane.

Conclusions:

• The CHX8 database provides a valuable resource for discovering novel hydrocarbon molecules.
• Many theoretically inaccessible strained and unsaturated hydrocarbons are predicted to be synthetically accessible.
• This work is expected to stimulate the synthesis of new molecules for diverse applications and aid machine learning model development.