Question

Consider thiol anion RS^- and alkoxy anion RO^- .Which of the following statements is correct?

• A. RS^- is less basic but more nucleophilic than RO^-
• B. RS- is more basic and more nucleophilic than RO-
• C. RS^- is more basic and less nucleophilic than RO^-
• D. RS- is less basic but less nucleophilic than RO-

Answer 1

The correct option is A

RS^- is less basic but more nucleophilic than RO^-

RS- is more nucleophilic but less basic than RO- .This opposite behaviour isbecause of the fact that basicity and nucleophilicity depends upon different factors .basicity is directly related to the strength of the H-element bond, while nucleophilicity is indirectly related to the electronegativity of the atom to which proton is attached.