Growth Pattern, Stability, and Properties of Complexes of C(2)H(5)OH and nCO(2) (n = 1–5) Molecules: A Theoretical Study

[Image: see text] This work is dedicated to theoretically investigate the formation process of C(2)H(5)OH···nCO(2) (n = 1–5) complexes and to shed light on the nature of interactions formed under the variation of CO(2) concentration. It is found that CO(2) molecules tend to locate around the polarized −OH group to interact with the lone pairs of the O atom. The interaction of ethanol with three CO(2) molecules (C(2)H(5)OH···3CO(2)) induces the most stable structure in the sequence considered. The atoms in molecules (AIM), NCIplot, and natural bond orbital (NBO) analyses point out that the O(ethanol)···C(CO(2)) tetrel bond overcomes hydrogen, chalcogen, and CO(2)···CO(2) tetrel-bonded interactions and mainly contributes to the strength of C(2)H(5)OH···nCO(2) (n = 1–5) complexes. All intermolecular interactions in the examined complexes are weakly noncovalent, and their positive cooperativity is evaluated to be slightly weaker than that of CO(2) pure systems. SAPT2+ and molecular electrostatic potential (MEP) calculations indicate that the electrostatic force is the main factor underlying the attractive interplay in the complexes of C(2)H(5)OH and CO(2).