Molecular polarisability. The conformation of 9-benzoylanthracene

Abstract

Dipole moments and molar Kerr constants (× 10¹²) at 25° are reported for the following as solutes in carbon tetrachloride: 9-benzoylanthracene (2·89D, –1000); 9-benzoyl-10-chloroanthracene (2·80D, –990); 9-benzoyl-10-bromoanthracene (2·82D, –1050); 9-benzoyl-10-cyanoanthracene (4·40D, +450); and 9-cyanoanthracene (4·13D, +790). The results indicate that 9-benzoylanthracene and the three substituted benzoylanthracenes have conformations in which the anthryl group is effectively perpendicular to the C–CO–C plane, while the phenyl group is inclined at about 45° to this plane.