Subhalides of tellurium

The tellurium subhalides represent a group of recently discovered compounds which have been investigated by the methods of solid-state and structural chemistry. Because of their high tellurium content and their crystal structures containing homonuclear tellurium connections they have attained significance as “modified tellurium structures”. As a consequence, tellurium subhalides have been the subject of various investigations in the fields of solid-state and chemical physics. In this paper a short survey of the group of tellurium halides is followed by detailed information on phase relations, preparation, crystal growth, and crystal structures of tellurium subhalides. Mössbauer investigations as well as optical, photoelectric, and electrical properties of the respective compounds are discussed. Solid-state galvanic cells containing tellurium subhalides have enabled the precise determination of relevant thermodynamic data