Inclusion and intercalation compounds of arsenic(iii) oxide polymorphs†

Abstract

Arsenic(III) oxycompounds exhibit rich structural chemistry due to the presence of stereoactive lone electron pairs on arsenic and secondary As⋯O bonds that stabilize variable conformations of chains and rings in the case of oxyanions and layers or molecules in the case of oxide. These two features are also responsible for the fact that arsenic(III) oxide forms inclusion and intercalation compounds. In this Highlight article, the discovery and characterization of molecular arsenic(III) oxide inclusion compounds with hydrogen and helium are presented. Also, structural studies of As₂O₃ intercalation compounds with alkali metal halides and pseudohalides are thoroughly described. Finally, future research avenues in the field are presented, which have become more appealing due to the recent literature reports of extraordinary optical properties of arsenic(III) oxide intercalates.