EFFECT OF TEMPERATURE ON THE SOLID-STATE MOLECULAR-STRUCTURE OF [FE-3(CO)(12)]

The molecular and crystal structure of. [Fe-3(CO)(12)] has been reinve stigated from single-crystal X-ray diffraction data collected at 100, 160, 250 and 320 K. The asymmetric bridging carbonyl ligands become pr ogressively more symmetric as the temperature is decreased. At the low est temperature the molecule possesses nearly exact C-2v symmetry. The crystal structure has been examined in the two limiting hypothetical P2(1) and P-1 crystals composing the disordered P2(1)/n structure.