The crystal and molecular structure of (S)-(+)- and racemic 9,10-dihydrodibenzo[c,g]phenanthrene

Abstract

The molecular and crystal structures of the title bridged 1,1′-binaphthyls, (+)-BBN and (±)-BBN, have been determined from single-crystal X-ray data and refined by least-squares methods to R factors of 0.0597 and 0.0437, respectively. The unit-cell dimensions of (+)-BBN are, a= 8.1423(7), c= 39.216(4)Å, space group P3₁2 1, with Z= 6, and of (±)-BBN, a= 20.018(2), c= 7.431(1)Å, space group P4₂bc with Z= 8. The dihedral angle between the mean planes of the two naphthalene planes in a given molecule are similar (50 and 49°) in the two crystals, as are other intramolecular bond angles and the bond distances. The molecular packing modes in the two crystal lattices are compared.