Which among the following complexes has square pyramidal geometry ?

Options

A. tatracarbonylnickel(0)
B. hexaamminecobalt(II) nitrate
C. pentacarbonyliron(0)
D. bis(acetylacetonato)oxovanadium(IV).

Explanation

To determine which of the given complexes has a square pyramidal geometry, we will analyze each complex step by step.

### Step 1: Analyze Tetra Carbonyl Nickel (Ni(CO)4)
- **Central Atom**: Nickel (Ni)
- **Ligands**: 4 Carbonyl (CO) ligands
- **Oxidation State**: 0
- **Electronic Configuration**: Ni in oxidation state 0 has the configuration 3d8 4s2.
- **Hybridization**: For 4 ligands, the hybridization is sp³.
- **Geometry**: The geometry corresponding to sp³ hybridization is tetrahedral.

**Conclusion**: Tetra Carbonyl Nickel does not have square pyramidal geometry.

### Step 2: Analyze Hexa Amine Cobalt Nitrate ([Co(NH3)6]NO3)
- **Central Atom**: Cobalt (Co)
- **Ligands**: 6 Ammonia (NH3) ligands
- **Oxidation State**: +2 (since the overall charge is +2 due to the nitrate)
- **Electronic Configuration**: Co in +2 state has the configuration 3d7.
- **Hybridization**: For 6 ligands, the hybridization is d²sp³.
- **Geometry**: The geometry corresponding to d²sp³ hybridization is octahedral.

**Conclusion**: Hexa Amine Cobalt Nitrate does not have square pyramidal geometry.

### Step 3: Analyze Penta Carbonyl Iron (Fe(CO)5)
- **Central Atom**: Iron (Fe)
- **Ligands**: 5 Carbonyl (CO) ligands
- **Oxidation State**: 0
- **Electronic Configuration**: Fe in oxidation state 0 has the configuration 3d6 4s2.
- **Hybridization**: For 5 ligands, the hybridization is dsp³.
- **Geometry**: The geometry corresponding to dsp³ hybridization is trigonal bipyramidal.

**Conclusion**: Penta Carbonyl Iron does not have square pyramidal geometry.

### Step 4: Analyze Bisacetyl Acetonato Oxo Vanadium (VO(acac)2)
- **Central Atom**: Vanadium (V)
- **Ligands**: 2 Bidentate acetyl acetonato ligands and 1 oxo (O) ligand
- **Oxidation State**: +5 (since it is bonded to two bidentate ligands and one oxo)
- **Hybridization**: The presence of 5 coordination sites leads to a hybridization of d²sp³.
- **Geometry**: The geometry corresponding to d²sp³ hybridization is square pyramidal.

**Conclusion**: Bisacetyl Acetonato Oxo Vanadium has square pyramidal geometry.

### Final Answer:
The complex that has square pyramidal geometry is **Bisacetyl Acetonato Oxo Vanadium (VO(acac)2)**.

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