Physical and chemical transformations of iron pentacarbonyl under pressure

Abstract

We have studied the physical and chemical transformations of iron pentacarbonyl (Fe(CO)5) in externally-heated diamond anvil cells using in-situ confocal micro-Raman spectroscopy. Raman spectroscopy of Fe(CO)5 were used to identify three different solid polymorphs and a polymeric solid found at high pressures, yielding the phase/chemical transformation diagram to 20 GPa. The pressure-induced Raman spectral changes suggest that liquid Fe(CO)5 undergoes several phase transformations at room temperature to phase I at 0.3 GPa, phase II at 1.5 GPa, and phase III at 4.9 GPa that polymerizes above 15.2 GPa.