Intra- and intermolecular interactions in substituted dithia[3.3]metacyclophanes

The conformational properties of and intramolecular hydrogen-bonding in dit hia[3.3]metacyclophanes carrying one or two amino groups on their internal positions were examined by their H-1-NMR and IR spectra and by X-ray struct ural analyses. It was suggested that an intramolecular hydrogen-bonding net work between the amino protons and bridge sulfur atoms is closely related t o the conformations of the cyclophanes. Crystal structural analyses of dith ia[3.3]metacyclophanes carrying an amino and a nitro group on their interna l positions were also carried out. It has been found that the molecules ass emble as one-dimensional array columns in the crystal owing to the intermol ecular pi-pi interaction and this columnar structure is deformed by the occ urrence of intermolecular hydrogen-bonding.