Question

Select the correct I.U.P.A.C name for $C_4{H}_{4}Fe(CO{)}_3$ complex :

• A. ${\eta }^4$ -cyclobutadiene tricarbonyliron (0)
• B. Tricarbonyl $({\eta }^4$ -cyclobutadienyl$)$ iron (0)
• C. Tricarbonyl $({\eta }^4$ -cyclobutadiene$)$ iron $\left(I\right)$
• D. Tricarbonyl $({\eta }^4$ -cyclobutadiene$)$ iron (0)

Answer 1

Answer: (D)

Tricarbonyl $({\eta }^4$ -cyclobutadiene$)$ iron (0)

$CO$ is a neutral ligand.

Cyclobutadiene is a $\pi$ accepted bonded ligand and is 4- membered carbon compound so ${\eta }^4$ is used before it.

It is also a neutral ligand. Thus, the oxidation state of iron is 0.

Option (D) is correct. The correct I.U.P.A.C name for $C_4{H}_{4}Fe(CO{)}_3$ complex is Tricarbonyl $({\eta }^4$ -cyclobutadiene$)$ iron(0)