Acta Chimica Slovaca (ACS) publishes papers on fundamental and applied aspects of chemistry, biochemistry, chemical technology, chemical engineering and process control, biotechnology and food technology. Welcome are also topics which include chemical aspects of materials, physical chemistry and chemical physics, analytical chemistry, macromolecular chemistry and biomedical engineering.

DFT and ab initio Calculations of Ionization Potentials, Proton Affinities and Bond Dissociation Enthalpies of Aromatic Compounds

Denisa Cagardová *, Martin Michalík, Erik Klein, Vladimír Lukeš, Zoran Marković a

Institute of Physical Chemistry and Chemical Physics, Slovak University of Technology in Bratislava, Radlinského 9, SK-812 37 Bratislava, Slovakia
a State University of Novi Pazar, Vuka Karadžića bb, 36300 Novi Pazar, Serbia

E-mail: * denisa.cagardova@stuba.sk

Abstract: Theoretical study of phenol, thiophenol, benzeneselenol, aniline and their para-amino and para-nitro derivatives is presented. Neutral molecules, their deprotonated forms, neutral radicals, and radical cations were studied using three Density Functional Theory (DFT) functionals as well as combined DFT and ab initio G4 method in order to calculate the N–H, O–H, S–H, and Se–H bond dissociation enthalpies (BDE), proton affinities of corresponding anions (PA) and ionization potentials (IP) of studied compounds. These quantities represent fundamental reaction enthalpies related to the radical scavenging action of primary antioxidants. Calculated values were compared with available experimental data to assess applicability of the computational approaches employed. M06-2X/6-311++G(d,p) and G4 methods showed the best agreement with the available experimental gas-phase reaction enthalpies.

Keywords: Antioxidant; radical; anion; electron-donating group; electron-withdrawing group

Full paper in Portable Document Format: acs_0349.pdf

Acta Chimica Slovaca, Vol. 12, No. 2, 2019, pp. 225—240, DOI: 10.2478/acs-2019-0032