Tautomerism and Microsolvation in 2-Hydroxypyridine/2-Pyridone

Abstract

The Fourier transform microwave spectra of the hydrated forms of the tautomeric pair 2-pyridinone/2-hydroxypyridine (2PO/2HP) have been investigated in a supersonic expansion. Three hydrated species, 2PO-H₂O, 2HP-H₂O, and 2PO-(H₂O)₂, have been observed in the rotational spectrum. Each molecular complex was confidently identified by the features of the ¹⁴N quadrupole hyperfine structure of the rotational transitions. The presence of water affects the tautomeric equilibrium -N═C(OH)- ↔ -NH-C(═O)-, which is shifted to the enol form for the bare molecules 2PO/2HP but to the keto tautomer for the hydrated forms.

Role of tautomerism in RNA biochemistry

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Hydrogen‐Bond Cooperativity in Formamide2–Water: A Model for Water‐Mediated Interactions

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Identification of Lactam–Lactim Tautomers of Aromatic Heterocycles in Aqueous Solution Using 2D IR Spectroscopy

“…Different levels of theory can lead to calculated energy differences of as much as 5 kcal/mol, and variation in the relative stability of species. 17,18 …”