Question

The correct pair of ambident nucleophiles are (i)$\mathrm{AgCN}/\mathrm{KCN}$ (ii) $\mathrm{RCOOAg}/\mathrm{RCOOK}$ (iii)${\mathrm{AgNO}}_2/{\mathrm{KNO}}_2$ (iv) $\mathrm{AgI}/\mathrm{KI}$

• A. (i) and (iii) only
• B. (ii) only
• C. (ii) and (iii) only
• D. (i) only

Answer 1

The correct option is A

(i) and (iii) only

The correct option is option A.

The explanation for the correct option:

1. Nucleophiles are chemicals that frequently donate electron pairs to electrophiles and form chemical bonds with them.
2. An ambident nucleophile is one that can carry nucleophilic attacks from two or more locations in the molecule.
3. Such attacks frequently lead to the production of more than one product.
4. is an anionic nucleophile in which the negative charge is delocalized over two atoms that are different from each other or two atoms that are similar but not equivalent.
5. Example of an ambident nucleophile is the Cyanide and Nitro group.
6. Cyanide$\left(\mathrm{CN}\right)$ is an ambident nucleophile because of the presence of two nucleophilic centers in cyanide, i.e. carbon and nitrogen. This indicates that both are donor atoms.
7. ${\mathrm{NO}}_2$is an ambident nucleophile because of the presence of two nucleophilic centers in the nitro group, namely nitrogen, and oxygen. This indicates that both are donor atoms.

The explanation for the incorrect options:

Option (B): (ii) only

1. $\mathrm{RCOOK}\to {\mathrm{RCOO}}^{-}+{\mathrm{K}}^{+}$
2. Because the electrons in RCOO- are conjugated, they cannot be attacked by a nucleophile freely.
3. Also, RCOO- is not an ambident nucleophile because it has only one position where a nucleophilic attack can occur.
4. Hence, it is an incorrect option.

Option (C): (ii) and (iii) only

1. $\mathrm{RCOOK}\to {\mathrm{RCOO}}^{-}+{\mathrm{K}}^{+}$
2. Because the electrons in RCOO- are conjugated, they cannot be attacked by a nucleophile freely.
3. Also, RCOO- is not an ambident nucleophile because it has only one position where a nucleophilic attack can occur.
4. Hence, it is an incorrect option.

Option (D): (i) only

1. ${\mathrm{NO}}_2$is an ambident nucleophile because of the presence of two nucleophilic centers in the nitro group, namely nitrogen, and oxygen. This indicates that both are donor atoms.
2. Hence, it is an incorrect option.

Final answer: The correct pair of ambident nucleophiles are $\mathrm{AgCN}/\mathrm{KCN}$ and ${\mathrm{AgNO}}_2/{\mathrm{KNO}}_2$