Betaines of pyridinium benzimidazolate containing polymethylene interannular spacers

Abstract

We report the first synthesis and relevant structural aspects of some simple examples of the betaines 5-7 and their immediate precursors 8-10. Inner salts 5b, 6b and 7b were isolated, whereas compounds 5a, 6a and 7a were transformed to dihydropyridine derivatives. Their liquid-crystal behavior was examined and for benzimidazolyl pyridinium bromide 8a the secondorder hyperpolarizability (β) was measured.