Back to basics: The case of ethane bond enthalpy terms

Bond strengths are key values for the prediction of molecular behavior (reactivity, spontaneity, etc.). The values of bond strengths are often not directly experimental ones, but rather are calculated from experimental data. Also, transferability of bond strength values is a still discussed subject. In this small communication several kinds of bond strengths and their transferability are addressed. Rearrangement enthalpies and apparent contradictions between their values and spontaneity of the process are analyzed. An alternative approach is proposed to explain these inconsistences for the case of ethane.