Question

What are organometallic compounds?

Answer 1

We have heard a lot about organometallic compounds. We can understand the definition of organometallic compounds from its name itself. Zeise’s salt is the first known organometallic compound. The chemistry of organometallic compounds is known as organometallic chemistry.

Complete step by step answer:
The chemical compounds which have at least one bond between metal and carbon atom of an organic compound. In organometallic compounds, nucleophilic carbon atoms helps to react with electrophilic carbon to form a new carbon-carbon bond. Generally these organometallic compounds are named as substituted metals, i.e. alkyl metal or alkyl metal halide etc.
For example, the chemical formula of Grignard reagent is ${{C}}{{{H}}_3}{{MgBr}}$. It is named as methyl magnesium bromide. ${{C}}{{{H}}_3}{{Li}}$ is named as methyl lithium.
The organometallic compounds are generally very reactive. Thus they are kept in organic solvents. Some properties of organometallic compounds are given below:
1.Low melting point
2.Insoluble in water
3.Soluble in ether
4.Highly reactive
Organometallic compounds are of three types. They are:
1.Main group
These are the organometallic compounds which have s or p block elements. E.g. ${{RMgX}}$.
2.Transition metal
These are the organometallic compounds which have d block elements. E.g. Wilkinson’s catalyst $\left[ {{{Rh}}{{\left( {{{PP}}{{{h}}_3}} \right)}_{{3}}}{{Cl}}} \right]$, Vaska’s complex $\left[ {{{IrPP}}{{{h}}_3}\left( {{{CO}}} \right)\left( {{{Cl}}} \right)} \right]$, etc.
3.Lanthanide and actinide organometallic compounds.
These are the organometallic compounds which have f block elements. E.g. Uranocene

Note: The properties of organometallic compounds is dependent on the type of carbon-metal bond. The structure of these compounds can be determined using $18 -$ electron rule. It is also known as an effective atomic number. When the compounds have $18$ valence electrons at the metal, then it is said to be stable. For example, ${{Ni}}{\left( {{{CO}}} \right)_4}$ and ${{Mo}}{\left( {{{CO}}} \right)_6}$ satisfies the $18 -$ electron rule.