Formation of carboxylic acid complexes with polyaromatic hydrocarbons of the coronene series. Quantum chemical modelling

• Published in: Journal of physics. Conference series Vol. 1658; no. 1; pp. 12044 - 12052
• Main Authors: Raksha, E V, Vysotsky, Yu B, Kartashynska, E S, Savoskin, M V
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 01.10.2020
• Subjects: Acetic acid; Acids; Binding; Carboxylic acids; Elongation; Enthalpy; Gibbs free energy; Hydrocarbons; Mathematical models; Modelling; Parameters; Physics; Polycyclic aromatic hydrocarbons; Quantum chemistry
• ISSN: 1742-6588; 1742-6596
• DOI: 10.1088/1742-6596/1658/1/012044

The paper presents the results of molecular modelling of the carboxylic acid interaction with polyaromatic hydrocarbons (PAH) of a coronene series in the framework of the semi-empirical PM6-DH2 method. It has been shown that the orientation of the acid molecule when all its atoms are in the plane parallel to the PAH one is the most preferable. Using the results of the thermodynamic parameters assessment, it was shown that for complexes of acetic acid with considered PAH the binding enthalpy and Gibbs free energy increase in the series from coronene to dicircumcoronene. An acid hydrocarbon radical elongation leads to an increase in the binding enthalpy and Gibbs free energy of carboxylic acids of the series CnH2n+1-COOH (n = 0 ÷ 5) with dicircumcoronene. Complexes of carboxylic acids with PAH are stabilized by nonvalent CH...CPAH interactions. It was found that the thermodynamic parameters of the complexes formation linearly correlate with the number of stabilizing CH...CPAH interactions for considered complexes of carboxylic acids CnH2n+1-COOH (n = 1 ÷ 5) with dicircumcoronene.