CO<sub>2</sub>Aggregation on Monoethanolamine: Observations from Rotational Spectroscopy
Fan Xie, Wenhao Sun, Pablo Pinacho, Melanie Schnell
Abstract
Abstract The initial stages of the gas‐phase nucleation between CO 2 and monoethanolamine were investigated via broadband rotational spectroscopy with the aid of extensive theoretical structure sampling. Sub‐nanometer‐scale aggregation patterns of monoethanolamine‐(CO 2 ) n , n =1–4, were identified. An interesting competition between the monoethanolamine intramolecular hydrogen bond and the intermolecular interactions between monoethanolamine and CO 2 upon cluster growth was discovered, revealing an intriguing CO 2 binding priority to the hydroxyl group over the amine group. These findings are in sharp contrast to the general results for aqueous solutions. In the quinary complex, a cap‐like CO 2 tetramer was observed cooperatively surrounding the monoethanolamine. As the cluster approaches the critical size of new particle formation, the contribution of CO 2 self‐assembly to the overall stability increases.