Question

Which of the following is not considered as an organometallic compound?
A.Ferrocene
B.Cis-platin
C.Ziese’s salt
D.Grignard reagent

Answer 1

We need to know and understand the definition of an organometallic compound and accordingly conclude as to which of the given options do not obey the definition. Organometallic compounds are those in which the carbon atoms of organic groups are directly linked to metal atoms. Organometallics also contain the compounds of elements such as boron, phosphorus, silicon, germanium, and antimony with organic groups.

Complete answer:
Chemical compounds that include at least one chemical link between a carbon atom in an organic molecule and a metal, such as alkaline, alkaline earth, and transition metals, and are occasionally expanded to include metalloids such as boron, silicon, and selenium. Bonds to 'inorganic' carbon, such as carbon monoxide (metal carbonyls), cyanide, or carbide, are typically regarded to be organometallic non addition to bonds to organyl fragments or molecules.
Understanding the concept of organometallic compounds, we evaluate each of the given compounds.
Ferrocene: The chemical formula of ferrocene is $[Fe{({C_5}{H_5})_2}]$. The metal element iron is attached to the carbon hence it is an organometallic compound.
Cis-platin: The chemical formula of cis-platin is $[PtC{l_2}{(N{H_3})_2}]$. This compound lacks a carbon atom although it has a metal. Hence it is not an organometallic compound.
Ziese’s salt: The chemical formula of Ziese’s salt is where the carbon as a part of ligand bonds to the central metal atom platinum. Hence, it is an organometallic compound.
Grignard reagent: The chemical formula of Grignard reagent is $R - MgX$ where $Mg$ is a metal and $R$ is any organic group. Hence, it is an organometallic compound.

Therefore, the correct option is option B because cis-platin does not obey the criteria to be called an organometallic compound.

Note:
Note that the given compounds can also be drawn out structurally to examine their bonds and to see where a metal is bonded to a carbon atom or not. Also, organometallic compounds must not be confused with metalorganic compounds. The phrase "metalorganic compound" refers to metal-containing compounds that lack direct metal-carbon bonds but contain organic ligands. This class includes metal -diketonates, alkoxides, dialkyl amides, and metal phosphine complexes.