Which of the following statement in correct with reference of `RS^(Theta) and RO^(Theta).`?

Options

A. `RS^(Theta)` is less basic and less nucleophilic than `RO^(Theta)`
B. `RS^(Theta)` is less basic and more nucleophilic than `RO^(Theta)`
C. `RS^(Theta)` is less basic and more nucleophilic than `RO^(Theta)`
D. `RS^(Theta)` is more basic but less nucleophilic than `RO^(Theta)`

Answer

To determine which statement is correct with reference to RS⁻ (thiolate ion) and RO⁻ (alkoxide ion), we need to analyze their nucleophilicity and basicity.

### Step-by-Step Solution:

1. **Understanding Nucleophilicity**:
- Nucleophilicity refers to the ability of a species to donate an electron pair to an electrophile. A stronger nucleophile is more likely to react with an electrophile.

2. **Comparing RS⁻ and RO⁻**:
- RS⁻ is the thiolate ion, while RO⁻ is the alkoxide ion.
- Both are negatively charged species and can act as nucleophiles.

3. **Size and Electronegativity**:
- Sulfur (S) in RS⁻ is larger and less electronegative than oxygen (O) in RO⁻.
- The larger size of sulfur means that the electron density is held less tightly compared to oxygen.

4. **Nucleophilicity**:
- Due to the larger size and lower electronegativity of sulfur, RS⁻ is a better nucleophile than RO⁻. This is because the electron pair on sulfur is more available for donation.

5. **Basicity**:
- Basicity refers to the ability of a species to accept protons (H⁺).
- Since RS⁻ is a better nucleophile, it is also less basic compared to RO⁻ because it is more stable and less likely to accept protons.

6. **Conclusion**:
- The correct statement is that RS⁻ is a better nucleophile but less basic than RO⁻. Therefore, the statement that RS⁻ is less basic is correct.

### Final Answer:
The correct statement is that RS⁻ is a better nucleophile and less basic than RO⁻.