Tautomeric pyridines. Part XII. The stabilisation of hydroxy-forms by intramolecular hydrogen-bonding
Abstract
A series of 10-hydroxy-1,7-phenanthrolines are shown to prefer the hydroxy- to the pyridone-form for both polar and nonpolar media. This tendency results both from stabilisation of the hydroxy-form by intramolecular hydrogen-bonding, similar examples of which are discussed, and from destabilisation of the pyridone form by electron repulsion terms.