title: rac-7,7',9,9'-Tetra-phenyl-9a,9a'-bi(7,8,9,9a-tetra-hydro-6aH-penta-leno[1,2,3-ij]naphthalen-8-one).
abstract: The racemic title compound, C(54)H(38)O(2), consists of two C-linked penta-leno[1,2,3-ij]naphthalenone moieties, the crowded aryl ring substitution on the cyclo-pentane rings forcing the two segments to assume a conformation which has pseudo-twofold rotational symmetry, with a dihedral angle between the naphthalene substituent groups of 55.30 (8)°. In each segment, the two phenyl rings have different conformational orientations, with inter-ring dihedral angles of 34.7 (2) and 49.63 (16)°. Each cyclo-pentane ring has the same relative configuration in its four chiral centres and together with the fused naphthalene ring assumes an overall chair-like conformation.
authors.affiliation: State Key Laboratory of Fine Chemicals and School of Chemical Engineering, Dalian University of Technology, Dalian 116012,  People's Republic of China.
authors.forename: Xiangdong
authors.initials: X
authors.lastname: Zhang
authors.forename: Junwei
authors.initials: J
authors.lastname: Ye
authors.forename: Weitao
authors.initials: W
authors.lastname: Gong
authors.forename: Yuan
authors.initials: Y
authors.lastname: Lin
authors.forename: Guiling
authors.initials: G
authors.lastname: Ning