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.

S—H Bond Dissociation Enthalpies in para- and meta- Substituted Thiophenols: Correlation with Thiophenolic C—S Bond Length

Lenka Rottmannová, Adam Vagánek, Ján Rimarčík *, Vladimír Lukeš, Erik Klein

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

E-mail: *

Abstract: For mono-substituted anilines, phenols, and thiophenols it has been found that N—H, O—H and S—H bond dissociation enthalpies (BDE) depend on Hammett constants approximately linearly. For substituents placed in meta position, linearity of found dependences is usually considerably worse in comparison to para-substituted molecules. Therefore, their applicability for prediction of changes in BDE using substituent Hammett constant may be limited. In this work, we have found that the length of thiophenolic C—S bond, R(C—S), or its shortening after hydrogen atom abstraction, DR(C—S), represent suitable descriptors of substituent induced changes in S—H BDE. For fifteen studied meta-substituted thiophenols, these geometry descriptors correlate with S—H BDEs considerably better than Hammett constants.

Keywords: DFT/B3LYP, Bond dissociation enthalpy, Thiophenol, Substituent effect, C—S bond length

Full paper in Portable Document Format: acs_0106.pdf

Acta Chimica Slovaca, Vol. 5, No. 1, 2012, pp. 37—41