Crystal and molecular structure of 5,10-epoxy-, 5,10-epithio-, 5,10-episeleno-, and 5,10-epitelluro-5,10-dihydroarsanthren

Abstract

The crystal and molecular structures of the eutropic series of compounds 5,10-epoxy-, 5,10-epithio-, 5,10-episeleno-, and 5,10-epitelluro-5,10-dihydroarsanthren have been fully elucidated by single-crystal X-ray diffraction studies. The molecules of each member of the series show the expected ‘butterfly’ conformation. The molecular geometry is quite similar for all the compounds, but small differences related to the different bonding and steric requirements of the Group VI heteroatom do occur. The dihedral angles about the As–As axis very from 104·4—113·7° in the four compounds.