Charting the chemical space of modular heterocyclic nucleophiles for CO₂ capture

Carbon capture and storage (CCS) is widely recognized as a pivotal strategy in the transition to a net-zero global economy. However, widespread implementation of CCS is hindered by challenges including the high energy demands associated with solvent regeneration after capture. π-conjugated heterocyclic nucleophiles present a promising alternative to traditional solvents, offering tunable CO₂ binding through the choice of nucleophilic center, heterocycle, and ring substitution. Employing a high-throughput, automated DFT pipeline, we generated a combinatorial virtual library of over 1,800 potential binders, elucidating structure-property relationships that govern their CO₂-binding thermodynamics. Our results highlight key design principles that enable fine-tuning of binding energetics. We find that guanidine, olefin, and carbene-based systems display a much broader range of binding energies compared to traditionally tertiary amines. These energetics can be modulated through the interplay of conformational, electrophilic, and nucleophilic properties of the attached heterocycle, with heteroatom-specific behavior. Additionally, we investigate how steric and electronic properties of substituents can be leveraged to further tune binding strength and regeneration temperature. This systematic exploration enhances our understanding of π-conjugated nucleophiles as viable components for the targeted design and development of efficient carbon capture materials.