Question

Which of the following species is not electrophilic in nature ?

• A. ${ BH_3}$
• B. $H_3\overset {\oplus}O $
• C. $ \overset{\oplus}N O_2$
• D. $\overset{\oplus}C l $

Answer 1

The Correct Option is B

 To determine which of the given species is not electrophilic in nature, we first need to understand what makes a species electrophilic. Electrophiles are electron-deficient species that seek electron-rich sites and typically accept electron pairs. They are often positively charged or lack a complete octet.

1. Consider the species: \({BH_3}\)
   • \({BH_3}\) is borane, a molecule with three hydrogen atoms bonded to boron.
   • Boron is an electron-deficient element in this context because it only has six valence electrons, making it a strong Lewis acid and therefore electrophilic.
2. Consider the species: \(H_3\overset {\oplus}O\)
   • This species represents the hydronium ion, \({H_3\overset {\oplus}O}\), which is protonated water.
   • It has a complete octet around the oxygen and carries a positive charge, making it more likely to donate a proton (acidic) rather than accept electrons (electrophilic).
3. Consider the species: \(\overset{\oplus}N O_2\)
   • This is the nitronium ion, \({NO_2^+}\), which is a well-known electrophile.
   • It lacks a complete octet around the nitrogen atom and is positively charged, making it highly electrophilic.
4. Consider the species: \(\overset{\oplus}C l\)
   • This species represents a positively charged chlorine, \({Cl^+}\).
   • Due to the positive charge and high electronegativity of chlorine, it acts as an electrophile.

Upon reviewing these species, it becomes evident that \(H_3\overset {\oplus}O\) (hydronium ion) is not electrophilic in nature because it acts more as a proton donor rather than seeking additional electrons.

Therefore, the species that is not electrophilic in nature is indeed the hydronium ion, \(H_3\overset {\oplus}O\).