In which of the following pairs both the molecules are non existing?

Options

A. `SF_(4)`,`OF_(4)`
B. `OF_(4)`,`OF_(6)`
C. `SF_(4)`,`SF_(6)`
D. `OF_(2)`,`OF_(4)`

Explanation

To determine which pair of molecules are non-existing, we will analyze the oxidation states and the ability of the elements to form compounds.

### Step-by-Step Solution:

1. **Identify the Molecules**: We are given pairs of molecules: SF4, OF4, OF6, OF2, and SF6.

2. **Analyze SF4**:
- Sulfur (S) can exhibit oxidation states of +2, +4, and +6.
- SF4 exists because sulfur can have a +4 oxidation state.

3. **Analyze OF4**:
- Oxygen (O) typically has oxidation states of -2, 0, and +2.
- Oxygen does not have the ability to exhibit +4 oxidation state because it lacks d-orbitals.
- Therefore, OF4 does not exist.

4. **Analyze OF6**:
- Similarly, for OF6, if we assume oxygen to have a +6 oxidation state, it would require the availability of d-orbitals, which oxygen does not have.
- Hence, OF6 does not exist.

5. **Analyze OF2**:
- OF2 is a stable molecule where oxygen is in the -2 oxidation state, which is valid.
- Therefore, OF2 exists.

6. **Analyze SF6**:
- SF6 is stable and exists because sulfur can exhibit a +6 oxidation state.
- Therefore, SF6 exists.

7. **Conclusion**:
- Based on the analysis, the pairs OF4 and OF6 are both non-existing molecules.
- Thus, the answer is **OF4 and OF6**.