POLYCYCLIC AROMATIC NITROGEN CATIONS

This chapter presents the synthesis of polycyclic aromatic nitrogen cations, as well as their chemical and physicochemical properties. The chemistry of bicyclic and tricyclic compounds is also discussed from a theoretical standpoint. The chapter discusses that there are two general types of polycyclic aromatic nitrogen cations: N-Alkyl quinolinium salts (Type A) and quinolizinium salts (Type B). Since the prefix azonia designates the cationic nitrogen, which is a part of cyclic structures, these two types of compounds are categorized as the azonia derivatives of polycyclic aromatic hydrocarbons. It reviews that the replacement of a bridgehead carbon of polycyclic aromatic hydrocarbons with nitrogen gives the azonia derivatives. Of the six possible tetracyclic benzenoid aromatic hydrocarbons, one can predict a total of 18 aromatic cations having bridgehead nitrogen. In case of compounds without symmetry, this happens because many isomeric compounds are possible due to the position of quaternary nitrogen. © 1992, Elsevier Science Publishers B.V.