Stability of doubly and triply H-bonded complexes governed by acidity-basicity relationships.

We used our recently proposed acidity-basicity interplay (ABI) model (Chem. Sci., 2018, 9, 4402) and the Jorgensen secondary interactions hypothesis (JSIH) to rationalise the experimentally observed trends in the formation constants of doubly and triply H-bonded systems with -NHO[double bond, length as m-dash]C- and -NHN- interactions. Unlike the JSIH, the ABI interpretation can explain the trends in the complexation of amide/imide homo- and heterodimers as well as ADA-DAD clusters. We found that the strongest H-bonds play a very important role, a condition which offers an alternative to the well established JSIH to modulate the stability of these relevant systems.