Theoretical study of the substituent effect on the hydrogen atom transfer mechanism of meta- and para-substituted benzenetellurols

The density functional theory and ab initio MP2 approach was used for the investigation of benzenetellurol and its mono-substituted derivatives. Contrary to the phenol and thiophenol, the gas-phase geometry of C6H5TeH is not planar. Analogously to the benzeneselenol, the benzenetellurol radical exhibits two different lower-lying electronic states. The ROB3LYP//UB3LYP/aug-cc-pVTZ-(PP) bond dissociation enthalpy (BDE) corresponding to the lowest-lying pi-state is 281 kJ mol(-1) and the BDE(Te-H) of the sigma-state is 296 kJ mol(-1). Finally, the substituent effect on the BDE(Te-H) for fourteen meta- and para-substituted benzenetellurols was discussed with respect to the congener C6H5XH (X = O, S, Se) derivatives. (C) 2016 Elsevier B.V. All rights reserved.