Covalent Hydration in Nitrogen-Containing Heteroaromatic Compounds: I. Qualitative Aspects

Abstract

This chapter discusses the qualitative aspects of the covalent hydration in nitrogen-containing heteroaromatic compounds. The experimental study of covalent hydration is performed and is found to be common in the pteridine series and in several simpler families of poly-azanaphthalenes. The methods used to diagnose this phenomenon, its occurrence in the various heterocyclic families, factors in the stabilization of the covalent hydrates, ring-opening, and the chemical and biological implications are also discussed in the chapter. The choice of methods to diagnose covalent hydration in nitrogen-containing heteroaromatic compounds depends largely on the ratio of hydrated to anhydrous species at equilibrium in the cation, neutral species, or anion. In the chapter, the triazanaphthalenes compounds are discussed in two separate groups: (1) the 1,2,3- and 1,2,4-triazanaphthalenes and (2) the 1,3,5-;1,3,6-; 1,3,7-; and 1,3,8-triazanaphthalenes. The factors useful in the stabilization of covalent hydrates are also reviewed in the chapter.