Question

Select the correct IUPAC name for \[Cr({C_6}{H_6}){(CO)_3}\].
A.$({\eta ^6} - benzene)tricarbonylchromium(0)$
B.$Tricarbonyl({\eta ^6} - benzene)chromate(0)$
C.$Tricarbonyl({\eta ^6} - benzene)chromium(0)$
D.$({\eta ^6} - benzene)tricarbonylchromium(0)$

Answer 1

Hint: In the given question it is asked about the correct IUPAC name of the given compound \[Cr({C_6}{H_6}){(CO)_3}\] due to the bond formation and the norms of the general nomenclature for the sake of complex compounds. Now after that we just have to keep the required data and facts step by step like the positive nature of chromium in bond formation and we can get the right answer which in this case is $({\eta ^6} - benzene)tricarbonylchromium(0)$

Complete Step by step Solution:
In the given question we have to find out the correct name for the given chemical compound given in the statement. The given compound is complex and has ligand bonds, so it needs some special nomenclature rules to find the names we need.
Now we have to mention which one of the given options is correct and follows the norms of the nomenclature of the complex compounds. So we just have to take it step by step and we can figure out the right answer.
The correct I.U.P.A.C name for \[Cr({C_6}{H_6}){(CO)_3}\] :
Here we can say that benzene is indulged in donation of $6$ electrons. Therefore the hapticity of it would be $6$.
Now after that there is the presence of three carbonyl groups in the compound which takes the formula to \[{(CO)_3}\].
Due to the positive nature of chromium in bond formation the name used is chromium not chromate.
And the oxidation state of the centre atom, $Cr$ is also written in the parenthesis bracket.
So that gives us the correct answer as $({\eta ^6} - benzene)tricarbonylchromium(0)$.
Therefore the right option would be the option $({\eta ^6} - benzene)tricarbonylchromium(0)$.

Hence, the correct answer is option D.

Note: A chemical nomenclature is a set of rules to generate systematic names for chemical compounds. The nomenclature used most frequently worldwide is the one created and developed by the International Union of Pure and Applied Chemistry (IUPAC).