Which of the following species is not electrophilic in nature?
- Cl
- BH3
- H3 O
- NO2
Answer
(3) H3 O
Solution
As per NCERT, electrophiles are electron-seeking reagents: positively charged species with an incomplete octet or neutral molecules with an electron-deficient atom.
Cl (chloronium ion) and NO2 (nitronium ion) are electrophiles.
BH3: boron has only six valence electrons ⇒ electron deficient ⇒ electrophile (Lewis acid).
H3 O: oxygen has a complete octet (three bonds and one lone pair); it cannot accept an electron pair, it only acts as a proton donor (Brønsted acid).
∴ H3 O is not electrophilic.
Answer: (3)