Causes of Reversal in Tautomeric Form Aromatic Resonance

Of course, this was before the invention of quantum mechanics, and they could not have foreseen the enormous literature that proton transfer reactions would generate in the next century and the conceptual problems this seemingly simple reaction would engender. The fact that the proton is at the borderline between classical and quantum mechanics is another complicating factor, of which some of the issues will be explored in Chapter 9. 

In the next few sections, we describe the influence of a number of parameters aromatic resonance, lone-pair and dipolar repulsion, internal hydrogen bonding, electronegative substituents, and the surrounding solvent on the relative stability of tautomeric forms. The remainder of this chapter is devoted to a brief history of tautomeric equilibria and tautomer dynamics. 

Causes of Reversal in Tautomeric Form Aromatic Resonance 

an important contrast is with 3 and 4, where an estimate for piperidine-2-one 3 is contrasted with the (corrected) value for 2-pyridone 4. In that case. 

2) Often, a tautomerization constant Ky is defined on the basis of the dominant tautomer in the gas phase. In [4], it is argued that this is not always good practice, and we prefer to use the enolization 

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