ap-9-(meta-tert-butylphenyl)fluorene.

The title compound, C(23)H(22), (I), crystallizes in an ap conformationThe designations sp (synperiplanar) and ap (antiperiplanar) for these fluorene rotamers are in accordance with Rule E-6.6, IUPAC Tentative Rules, Section E, Fundamental Stereochemistry [J. Org. Chem. (1970), 35, 2861]. and its melt readily recrystallizes on cooling, in contrast to the corresponding 9-fluorenol compound, (II), which is sp and which melts without decomposition and fails to recrystallize over a long period. Both of these differences are ascribed to the intermolecular hydrogen bonding in (II), which is absent in (I) and which leads to distinctly different molecular packing in the two compounds.