The theoretical assessment and prediction of CBr bond dissociation enthalpies

The CBr bond dissociation enthalpies (BDE) of various bromides were assessed and predicted using quantum chemical methods, including composite high-level ab initio and a number of density functional theory (DFT) methods. The systematic evaluation of the DFT CBr BDEs against available experimental ones indicated that the PBE1KCIS method gave the highest accuracy (the root mean square error is 7.5 kJ/mol). Then we used this method to examine the substituent effects, as well as the remote substituent effects on CBr BDEs of different kinds of CBr bonds. In addition, the CBr BDEs of typical five- and six-membered heterocyclic bromides at the same level were also investigated.