Both 9-(o-tert-butylphenyl) fluorene (C23H22) and 9-(o-tert-butylphenyl)-9-fluorenol (C23H22O) maintained sp rotameric structures exclusively in crystalline form as well as in solution. This result is in contrast to that obtained for the corresponding 9-(o- isopropylphenyl) fluorene and 9-(o-isopropylphenyl)-9-fluorenol. In-plane sterically imposed distortion of the tert-butyl group is exhibited in sp-9-(o-tert-butylphenyl) fluorene and to a ...