How Hydrogen Bonding Amplifies Isomeric Differences in Pyridones toward Strong Changes in Acidity and Tautomerism was written by Buechner, Robby;Fondell, Mattis;Mascarenhas, Eric J.;Pietzsch, Annette;Vaz da Cruz, Vinicius;Foehlisch, Alexander. And the article was included in Journal of Physical Chemistry B in 2021.Product Details of 626-64-2 This article mentions the following:
Steric hindrance of hydration and hydrogen bond enhancement by localized charges have been identified as key factors for the massive chem. differences between the hydroxypyridine/pyridone isomers in aqueous solution While all isomers occur mainly in the hydroxypyridine form in the gas phase, they differ by more than 3 orders of magnitude both in their acidity and tautomeric equilibrium constants upon hydration. By monitoring the electronic and solvation structures as a function of the protonation state and the O– substitution position on the pyridine ring, the amplification of the isomeric differences in aqueous solution has been investigated. Near-edge X-ray absorption fine structure (NEXAFS) measurements at the N K-edge served as the probe of the chem. state. The combination of mol. dynamics simulations, complete active space SCF (CASSCF), and time-dependent d. functional theory (TD-DFT) spectral calculations contributes to unraveling the principles of tautomerism and acidity in multiple biochem. systems based on tautomerism. In the experiment, the researchers used many compounds, for example, Pyridin-4-ol (cas: 626-64-2Product Details of 626-64-2).
Pyridin-4-ol (cas: 626-64-2) belongs to pyridine derivatives. Pyridine has a dipole moment and a weaker resonant stabilization than benzene (resonance energy 117 kJ·mol−1 in pyridine vs. 150 kJ·mol−1 in benzene). One of the examples of pyridines is the well-known alkaloid lithoprimidine, which is an A3 adenosine receptor antagonist and N,N-dimethylaminopyridine (DMAP) analog, commonly used in organic synthesis.Product Details of 626-64-2