6,6-Diphenylfulvene at 140K

The title compound, C₁₈H₁₄, crystallizes with two molecules in the asymmetric unit, which differ only in the angle between the phenyl rings and the fulvene moiety. The two double bonds of the cyclopentadiene moiety are shortened [1.352 (2) and 1.353 (2) Å] in the title compound compared with the range found in its metal complexes. (1.381-1.520 Å), The bond joining these two double bonds is generally shorter in the metal complexes than in the title compound [1.467 (2) and 1.468 (2) Å], but there are exceptions. A conformational analysis of the title compound with the molecular modelling program MOMO [Bolte, Beck & Egert (1991). Molecular Modelling Program MOMO. University of Frankfurt, Germany] shows only one minimum on the energy hypersurface, where both phenyl rings form an angle of 56.6° with the fulvene moiety.

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