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.

Applicability of DFTB+ Method for the Calculations of O–H Bond Dissociation Enthalpies of Phenols

Lenka Rottmannová *, Ján Rimarčík, Tibor Veselý, Erik Klein, Vladimír Lukeš

Institute of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, SK-812 37 Bratislava, Slovak Republic

E-mail: * lenka.rottmannova@stuba.sk

Abstract: In this work, O–H bond dissociation enthalpies (BDE) of non-substituted phenol and 26 meta- and para-substituted phenols were calculated using semiempirical DFTB+ method. In comparison with available experimental BDE values, calculated BDEs are overestimated by ca 40 kJ mol–1. DFTB+ method predicts lower substituent induced changes in BDE in comparison with experimental values. On the other hand, the found changes in O–H BDEs are in accordance with computationally significantly more demanding DFT/B3LYP/6-311++G** method. Obtained results show that DFTB+ method may be successfully employed for the fast estimation of substituent induced changes in phenolic O–H bond dissociation enthalpies.

Keywords: BDE, Hydrogen Atom Transfer Mechanism, Substituent effect, Antioxidant

Full paper in Portable Document Format: acs_0064.pdf

Acta Chimica Slovaca, Vol. 3, No. 2, 2010, pp. 12—19