Tuning the Binding Strength of Even and Uneven Hydrogen-Bonded Arrays with Remote Substituents.

ABSTRACT: We investigated the tunability of hydrogen bond strength by altering the charge accumulation around the frontier atoms with remote substituents. For pyridine···H₂O with NH₂ and CN substituted at different positions on pyridine, we find that the electron-withdrawing CN group decreases the negative charge accumulation around the frontier atom N, resulting in weakening of the hydrogen bond, whereas the electron-donating NH₂ group increases the charge accumulation around N, resulting in strengthening of the hydrogen bond. By applying these design principles on DDAA-AADD, DADA-ADAD, DAA-ADD, and ADA-DAD hydrogen-bonded dimers, we find that the effect of the substituent is delocalized over the whole molecular system. As a consequence, systems with an equal number

SUBMITTER: van der Lubbe SCC 

PROVIDER: S-EPMC7667637 | biostudies-literature | 2020 Nov

REPOSITORIES: biostudies-literature