Iron compounds: iron pentacarbonyl

iron symbol icon

The iron in iron pentacarbonyl formally is in the oxidation state 0.

Crystal structure of iron pentacarbonyl

Iron pentacarbonyl

  • Formula as often written: Fe(CO)5
  • Hill system formula: C5Fe1O5
  • CAS registry number: [13463-40-6]
  • Formula weight: 195.895
  • Class: carbonyl complex organometallic


  • iron pentacarbonyl
  • iron(O) carbonyl
  • iron pentacarbonyl
  • pentacarbonyl iron

Physical properties

  • Colour: yellow
  • Appearance: oily liquid. Toxic!!
  • Melting point: -20.0°C
  • Boiling point: 103°C
  • Density: 1490 kg m-3 (liquid)


Coming soon...

Element analysis

Element percentages for the elements in iron pentacarbonyl
Element %
C 30.66
Fe 28.51
O 40.84


Not available

Solid state structure

  • Geometry of iron: 5 coordinate: trigonal bipyramidal
  • Prototypical structure:

Crystal structure of iron pentacarbonyl

Isotope pattern

What follows is the calculated isotope pattern for the Fe(CO)5 unit with the most intense ion set to 100%.

Formula: Fe1C5O5

mass  %
194   6.3 ___
195 0.4
196 100.0 __________________________________________________
197 8.2 ____
198 1.6 _
199 0.1
200 0.0


The data on these compounds pages are assembled and adapted from the primary literature and several other sources including the following.

  • R.T. Sanderson in Chemical Periodicity, Reinhold, New York, USA, 1960.
  • N.N. Greenwood and A. Earnshaw in Chemistry of the Elements, 2nd edition, Butterworth, UK, 1997.
  • F.A. Cotton, G. Wilkinson, C.A. Murillo, and M. Bochmann, in Advanced Inorganic Chemistry, John Wiley & Sons, 1999.
  • A.F. Trotman-Dickenson, (ed.) in Comprehensive Inorganic Chemistry, Pergamon, Oxford, UK, 1973.
  • R.W.G. Wyckoff, in Crystal Structures, volume 1, Interscience, John Wiley & Sons, 1963.
  • A.R.West in Basic solid state chemistry Chemistry, John Wiley & Sons, 1999.
  • A.F. Wells in Structural inorganic chemistry, 4th edition, Oxford, UK, 1975.
  • J.D.H. Donnay, (ed.) in Crystal data determinative tables, ACA monograph number 5, American Crystallographic Association, USA, 1963.
  • D.R. Lide, (ed.) in Chemical Rubber Company handbook of chemistry and physics, CRC Press, Boca Raton, Florida, USA, 77th edition, 1996.
  • J.W. Mellor in A comprehensive treatise on inorganic and theoretical chemistry, volumes 1-16, Longmans, London, UK, 1922-1937.
  • J.E. Macintyre (ed.) in Dictionary of inorganic compounds, volumes 1-3, Chapman & Hall, London, UK, 1992.

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iron atomic number