The conformation of the title molecule along with the atom-numbering scheme is shown in Fig. 1. The molecule contains one fused-ring system (A/B) and two phenyl rings (C and D). All three aromatic rings, A, C and D, are planar [deviations of the atoms from their least-squ~es planes are within the range -0.018(1)- 0.025 (1) A], while ring B is puckered. In ring B, atoms C2 and 025 deviate by 0.423 (3) and -0.216(3)A, respectively, from the least-squares plane ...