Growth Pattern, Stability, and Properties of Complexes of C2H5OH and n CO2 (n = 1-5) Molecules: A Theoretical Study

Cam-Tu Dang Phan; Nguyen Thi Ai Nhung; Nguyen Tien Trung

doi:10.1021/acsomega.0c00948

Growth Pattern, Stability, and Properties of Complexes of C₂H₅OH and n CO₂ (n = 1-5) Molecules: A Theoretical Study

ACS Omega. 2020 Jun 10;5(24):14408-14416. doi: 10.1021/acsomega.0c00948. eCollection 2020 Jun 23.

Authors

Cam-Tu Dang Phan¹, Nguyen Thi Ai Nhung², Nguyen Tien Trung¹

Affiliations

¹ Laboratory of Computational Chemistry and Modelling (LCCM), Department of Chemistry, Quy Nhon University, 170 An Duong Vuong Street, Quy Nhon City 590000, Vietnam.
² Department of Chemistry, University of Sciences, Hue University, 77 Nguyen Hue Street, Hue City 530000, Vietnam.

Abstract

This work is dedicated to theoretically investigate the formation process of C₂H₅OH···nCO₂ (n = 1-5) complexes and to shed light on the nature of interactions formed under the variation of CO₂ concentration. It is found that CO₂ 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 CO₂ molecules (C₂H₅OH···3CO₂) 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_CO₂ tetrel bond overcomes hydrogen, chalcogen, and CO₂···CO₂ tetrel-bonded interactions and mainly contributes to the strength of C₂H₅OH···nCO₂ (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 CO₂ 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 C₂H₅OH and CO₂.