Organometallic compounds are those in which a metal atom is directly bonded to a carbon atom of an organic group. These compounds can exhibit different types of bonding, including sigma (\( \sigma \)) bonds, pi (\( \pi \)) bonds, or a combination of both.
Step 1: Analyze the Bonding in the Options.
Cobaltocene, Ruthenocene, and Ferrocene: These are sandwich compounds. In these compounds, the metal atom (such as cobalt in cobaltocene or iron in ferrocene) forms \( \pi \)-bonds with the aromatic cyclopentadienyl ligands. These compounds involve the interaction of metal and ligand through \( \pi \)-bonds, which are different from sigma bonds.
Grignard's reagent: In contrast, Grignard's reagent (RMgX) involves a direct metal-carbon sigma bond. In Grignard reagents, such as \( \text{CH}_3\text{MgBr} \), the magnesium (Mg) atom forms a \( \sigma \)-bond with the carbon (C) of the methyl group (\( \text{CH}_3 \)), making it a classic example of a sigma-bonded organometallic compound.
Step 2: Example of Grignard's Reagent.
Grignard reagents are typically represented as \( \text{RMgX} \), where:
The \( \sigma \)-bond between the magnesium and carbon atoms in \( \text{RMgX} \) is a defining feature of this type of organometallic compound. For example, in \( \text{CH}_3\text{MgBr} \) (methylmagnesium bromide), the carbon in the methyl group is directly bonded to magnesium via a sigma bond.
List-I | List-II | ||
(A) | [Co(NH3)5(NO2)]Cl2 | (I) | Solvate isomerism |
(B) | [Co(NH3)5(SO4)]Br | (II) | Linkage isomerism |
(C) | [Co(NH3)6] [Cr(CN)6] | (III) | Ionization isomerism |
(D) | [Co(H2O)6]Cl3 | (IV) | Coordination isomerism |
List-I | List-II | ||
(A) | 1 mol of H2O to O2 | (I) | 3F |
(B) | 1 mol of MnO-4 to Mn2+ | (II) | 2F |
(C) | 1.5 mol of Ca from molten CaCl2 | (III) | 1F |
(D) | 1 mol of FeO to Fe2O3 | (IV) | 5F |