Six-membered Rings with Two or More Heteroatoms with at least One Selenium or Tellurium

Abstract

This chapter deals with the chemistry of six-membered ring heterocycles containing two or more heteroatoms, at least one of which is a selenium or tellurium atom. The heterocyclic systems discussed include diselenanes, oxaselenanes, oxaselenins, diselenins, thiaselenins, ditellurins, selenanthrenes, thiaselenanthrenes, telluranthrenes, triselenanes, selenazines, oxaselenazines, selenadiazines, selenatriazines, and diselenazines. Some related heterocyclic structures are also described. Theoretical studies in this area are summarized, including calculations on the structures and reactivity of these molecules. The techniques used to confirm the structures of many of these heterocyclic compounds – in particular, X-ray crystallography and NMR spectroscopy – are highlighted, and other spectroscopic techniques which are important in this area of research are noted. The conformational properties of a number of the nonrigid representatives of this class of molecules are also described. The detailed chemical properties, reactions, and preparations of these molecules are reviewed. When possible, comparisons between the selenium and tellurium compounds and their sulfur analogs are made. The biological effects of a number of compounds in this series are reported including their potential utility as antimicrobial agents and their antitumor activities. Finally, the potential technical utility of a number of these compounds, particularly as organic semiconductors, is described.