In the given complexes:
Let's analyze each complex:
\([Cr(CO)_6]:\) Chromium is in the +2 oxidation state, and it has d6 electron configuration. It can exhibit synergic bonding due to back-bonding.
\([Mn(CO)_5]:\) Manganese is in the +1 oxidation state, and it has d7 electron configuration. It can exhibit synergic bonding due to back-bonding.
\([Mn_2(CO)_{10}]:\) Manganese is in the +1 oxidation state here as well. The molecule contains a manganese-manganese bond, and each manganese can exhibit synergic bonding with the surrounding CO ligands.
All three complexes are likely to exhibit synergic bonding. CO ligand shows synergic bonding, so all complexes can show synergic bonding.
Therefore, the number of complexes that will exhibit synergic bonding is 3.
The metal-carbon bond possesses both the σ and π character in a metal carbonyl. The synergic effect produced by the metal-ligand bond strengthens the bond between the carbonyl molecule and the metal. The types of bonding that exist in metal carbonyls are as follows:
They are found to dissociate in various solutions. The stability of a coordination compound in a solution mainly depends on the degree of association between the two species involved in the state of equilibrium. For the formation of the compound quantitatively the stability of any complex is given by the magnitude of the equilibrium constant. For instance,
A + 4B→ AB4