2016, Kazakbayeva, Zhanna, Zhumagali, Shingis, Mahboob, Abdulla, O'Reilly, Robert

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).

2016, Garifullina, Ainash, Mahboob, Abdulla, O'Reilly, Robert

We herein report a dataset of 28 homolytic C–Cl bond dissociation energies (BDEs) (to be known as the CCl28 dataset), obtained using the benchmark-quality W1w thermochemical protocol. This set contains chlorinated organic molecules that consist of either sp3-, sp2- or sp-hybridized C–Cl bonds. The species in this set have C–Cl BDEs (at 298 K) that differ by as much as 168.4 kJ mol^–1, with allyl chloride having the lowest BDE (291.7 kJ mol^–1) and 1-chloroprop-1-yne having the largest (460.1 kJ mol^–1). Given the benchmark quality of the CCl28 dataset, it may serve as a useful reference for assessing the performance of more approximate quantum chemical methods, such as density functional theory (DFT) and double-hybrid DFT methods.