On the molecular conformation of (E)-1,2-Di(9-anthryl)ethene. X-ray structure analyses of the parent compound and its 10,10'-dibromo derivative

Abstract

Two non-planar ground state conformations have been established by X-ray diffraction analyses of (E)-1,2-di(9-anthryl)ethene (1) and its 10,10'-dibromo derivative (2). The parent compound is characterized by a twofold axis of symmetry, the angle between the plane of the anthracene and that of the ethene being 55.1º. The angle between the two anthracene π-systems is 69.8º. The dibromo derivative (2) is characterized by a centre of symmetry, and the two anthracene π-systems are aligned parallel. The angle of twist between the plane of the anthracene and that of the ethene is 60.7º.