Plastic Phase of Formylferrocene Studied by X-Ray Diffraction and Mössbauer Spectroscopy

The structures of both the crystal and the plastic phases of formylferrocene have been determined to be orthorhombic by single-crystal X-ray diffraction. The structural change proposes a mechanism of the transition that postulates the translational molecular motion along the a-axis. Mössbauer spectra observed in the plastic phase show little fluctuation of the electric field gradient ascribed to the orientational disorder between x, y, and z axes of the molecule.