Metal Carbonyl
A coordination compound in which carbon monoxide molecules are bonded to a metal centre.
Formula / equation
M(CO)ₙ
Unit
Dimensionless
In depth
Carbon monoxide donates a sigma lone pair to the metal and accepts electron density back from filled metal d orbitals into its pi antibonding orbital. This synergic bonding strengthens the metal–carbon bond while weakening the C–O bond, which is detectable as a lowered infrared stretching frequency.
Examples in the real world
Ni(CO)₄, used in the Mond process to purify nickel; Fe(CO)₅ and Cr(CO)₆ as synthetic precursors.