Homolytic C–Br bond dissociation energies obtained by means of the G4 thermochemical protocol

Abstract

Abstract Knowledge of the energies required to induce homolytic cleavage of the C–Br bonds of brominated organic molecules, a process that affords carbon-centered radicals and Br • , is of fundamental importance. Although some data pertaining to the strength of C–Br bonds can already be found in the literature, the chemical diversity of the species for which bond dissociation energies (BDEs) are available is somewhat limited. In this data article, we report a comprehensive set of homolytic C–Br BDEs, obtained using the G4 thermochemical protocol, for brominated organic molecules with wide structural diversity. The species in this set have C–Br BDEs (at 298 K) that differ by as much as 188.3 kJ mol –1 , with α-bromoalanine having the lowest BDE (214.1 kJ mol –1 ) and 1-bromobut-1-yne having the largest (402.4 kJ mol –1 ). Of particular relevance to biological systems are the BDEs of 8-bromoguanine (345.3 kJ mol –1 ), 8-bromoadenine (345.6 kJ mol –1 ), 5-bromocytosine (348.8 kJ mol –1 ) and 5-bromouracil (350.3 kJ mol –1 ).