Molecular motion of ferrocene in a faujasite-type zeolite: A quasielastic neutron scattering study

We study the molecular motion of ferrocene Fe(C(5)H(5))(2) locked up in the supercages of KY zeolite at temperatures 22 K less than or equal to T less than or equal to 238 K by means of quasielastic neutron scattering, The geometry of the motion is determined to be a 5-fold internal jump reorientation of the cyclopentadienyl C(5)H(5) rings around the symmetry axis of the ferrocene molecule. We also obtain the mean residence time for these jumps as well as the activation energy for the process. We compare with NMR results: on ferrocene in faujasite-type zeolites and with quasielastic neutron scattering results on pure ferrocene.