Experimental

R factor = 0.048; wR factor = 0.130; data-to-parameter ratio = 16.6. In the title compound, C20H18O2, the fused-ring systems are essentially planar (r.m.s. deviations of the nine fitted atoms = 0.009 and 0.027 Å) and exhibit an orthogonal relationship [dihedral angle = 79.83 (5)]. To a first approximation, the ketone-O atoms are directed to opposite sides of the molecule. A three-dimensional architecture arises in the crystal packing owing to C—H O, C—H and – interactions [between centrosymmetrically related benzene rings with centroid– centroid distance = 3.7647 (10) Å]. Related literature For the biological activity of related indan-1-one derivatives, see: Vera-DiVaio et al. (2009). For a related structure see: Asiri et al. (2012)