Related Experiment Video
Updated: Sep 13, 2025

CD Spectroscopy to Study DNA-Protein Interactions
Published on: February 10, 2022
DNA base pairs: the effect of the aromatic ring on the strength of the Watson-Crick hydrogen bonding
Celine Nieuwland1, Michiel J van Well1, Laia Guillaumes2
1Department of Chemistry and Pharmaceutical Sciences, Amsterdam Institute for Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands. c.nieuwland@vu.nl.
Abstract:
The aromatic ring in DNA bases affects the Watson-Crick binding strength. Our quantum-chemical analyses, which compare the hydrogen bonding between the DNA bases and unsaturated analogs lacking the aromatic ring, reveal that this arises not from π-resonance assistance but from the electron-withdrawing (purines) or electron-donating (pyrimidines) effect of the heteroatom-containing ring on the frontier atoms. This electron redistribution modulates the electrostatics, steric Pauli repulsion, and σ-orbital interactions upon hydrogen bonding.
Related Concept Videos
DNA Base Pairing
π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds
DNA as a Genetic Template
NMR Spectroscopy of Benzene Derivatives
NMR Spectroscopy of Aromatic Compounds
Basicity of Aromatic Amines

