The tautomeric behavior of 1-(2-pyridinyl)-1H-pyrazol-5-ols has been investigated in solution using UV–vis and NMR spectroscopies and DFT quantum-chemical calculations. The study has been focused on the influence of the molecular structure, solvents, and acid addition protonation. The tautomerism has been considered in light of the possible long-range intramolecular proton transfer and tautomeric switching under […]