Molecular Structures of Di(9-anthryl)Methanol and Di(9-anthryl) Ketone

Abstract

The molecular structures of di(9-anthryl)methanol (1) and di(9-anthryl) ketone (2) have been established by X-ray diffraction. The asymmetric unit of di(anthryl)methanol consists of two molecules in which the dihedral angle between the anthracene moieties is 81.4 and 86.3 respectively; steric interaction between the anthracene moieties results in them subtending angles of 115.0(7) and 115.8(8)º at the central carbon atom, and with unsymmetrical exocyclic angles at their point of attachment. In di(9-anthryl) ketone the planes of the anthracene systems are twisted out of the plane of the carbonyl group by 48.8 and 52.2º respectively, so that the dihedral angle between the two aromatic ring systems is 87.3º. The structures of di(anthryl)methanol and di(anthryl) ketone are discussed with respect to their different modes of photochemical isomerization by intramolecular cycloaddition.