Abstract
The phase transition in crystalline ferrocene was investigated by following the intensity change with temperature of two infrared absorption bands associated with inactive molecular modes. It is suggested that at low temperatures there is an ordered lattice with noncentrosymmetric sites. There is no abrupt change in intensity at the phase transition indicating the persistence of the low-temperature short-range order into the high-temperature phase. The present study supports the suggested structure for the high-temperature phase in which there is a centrosymmetric lattice containing a predominant number of staggered molecules.