Structure and Spectroscopy of Iron Pentacarbonyl, Fe(CO)₅.

ABSTRACT: We have re-investigated the structure and vibrational spectroscopy of the iconic molecule iron pentacarbonyl, Fe(CO)₅, in the solid state by neutron scattering methods. In addition to the known C2/c structure, we find that Fe(CO)₅ undergoes a displacive ferroelastic phase transition at 105 K to a P1̅ structure. We propose that this is a result of certain intermolecular contacts becoming shorter than the sum of the van der Waals radii, resulting in an increased contribution of electrostatic repulsion to these interactions; this is manifested as a strain that breaks the symmetry of the crystal. Evaluation of the strain in a triclinic crystal required a description of the spontaneous strain in terms of a second-rank tensor, something that is feasible

SUBMITTER: Fortes AD 

PROVIDER: S-EPMC9523711 | biostudies-literature | 2022 Sep

REPOSITORIES: biostudies-literature