Efficient estimation of bond dissociation energies of organic compounds

Chemical reactions can be generally regarded as reorganization of chemical bonds through bond dissociation and formation. In this respect the fundamental energetic term “bond dissociation energy (BDE),” which describes the minimum energy required for homolysis of a bond in elementary bond-breaking step under standard conditions, should be the key factor to rationally understand chemical processes in terms of mechanism, reactivity and selectivity. This is especially imperative for development of artificial intelligence (AI) chemistry in the background of big data because it provides not only the necessary data but also hints for establishing descriptor sets and specific algorithms. However, till present, the known number of BDEs measured by experiments is only about 20 thousands, in stark contrast to the number of registered molecules of over 190 million known today. To narrow down the gap, in this mini-review, we introduce a quite facile way, the “anchoring method,” for efficient and satisfactory estimations of numerous BDEs of various complicated molecules whose BDEs are inconvenient to derive. The advantages and applicability of the anchoring method in comparison with those by the previous group additivity (GA) scheme and by computations are also addressed.