For metal complexes (i) `[PtCl_(3)(C_(2)H_(4))]^(-)` and (ii) `[PtCl_(3)(C_(2)F_(4))]^(-)` the correct statement is/ are that:

Options

A. Carbon-carbon bond length is same both in (i) and (ii)
B. carbon-carbon bond length in (i) is smaller than in (ii)
C. carbon-carbon bond length in (i) is larger than in (ii).
D. chelation takes place in both the complexes.

Explanation

To solve the problem regarding the metal complexes \([PtCl_3(C_2H_4)]^{-}\) and \([PtCl_3(C_2F_4)]^{-}\), we need to analyze the characteristics of these complexes, particularly focusing on the bond lengths and the effects of substituents on the alkene.

### Step-by-Step Solution:

1. **Identify the Complexes**:
- The first complex is \([PtCl_3(C_2H_4)]^{-}\).
- The second complex is \([PtCl_3(C_2F_4)]^{-}\).

2. **Analyze the Alkene Substituents**:
- In the first complex, the alkene is ethylene \((C_2H_4)\), which has hydrogen atoms attached to the carbon atoms.
- In the second complex, the alkene is tetrafluoroethylene \((C_2F_4)\), where fluorine atoms replace the hydrogen atoms.

3. **Consider Electronegativity**:
- Fluorine is more electronegative than hydrogen. This affects the hybridization of the carbon atoms in the alkene.
- The presence of fluorine increases the s-character of the carbon-carbon bond in \([PtCl_3(C_2F_4)]^{-}\) compared to \([PtCl_3(C_2H_4)]^{-}\).

4. **Evaluate Carbon-Carbon Bond Length**:
- Higher s-character in a bond results in a shorter bond length. Therefore, the carbon-carbon bond in \([PtCl_3(C_2F_4)]^{-}\) will be shorter than in \([PtCl_3(C_2H_4)]^{-}\).
- Thus, the bond length in \([PtCl_3(C_2H_4)]^{-}\) is longer than in \([PtCl_3(C_2F_4)]^{-}\).

5. **Conclusion on Bond Lengths**:
- The carbon-carbon bond length in the first complex \([PtCl_3(C_2H_4)]^{-}\) is greater than that in the second complex \([PtCl_3(C_2F_4)]^{-}\).

6. **Evaluate Chelation**:
- Chelation refers to the formation of multiple bonds between a ligand and a central metal atom. In this case, both complexes do not exhibit chelation as they have only one alkene ligand coordinated to platinum.

### Final Answer:
The correct statement is:
- The carbon-carbon bond length in \([PtCl_3(C_2H_4)]^{-}\) is greater than that in \([PtCl_3(C_2F_4)]^{-}\).