The species formed on fluorination of phosphorus pentachloride in a polar organic solvent are

The correct answer is:

$[{\mathrm{PCl}}_4{]}^{+}[{\mathrm{PClF}}_2{]}^{-}\text{and}[{\mathrm{PCl}}_4{]}^{+}[{\mathrm{PF}}_6{]}^{-}$

Step-by-step Explanation:

1. Ionization of Phosphorus Pentachloride:
In a polar organic solvent, phosphorus pentachloride (PCl₅) ionizes to form ionic complexes containing a tetrahedral cation and an octahedral anion. In solid state or polar solvents, PCl₅ auto-ionizes as:

$2{\mathrm{PCl}}_5\rightleftharpoons {\left[{\mathrm{PCl}}_4\right]}^{+}+{\left[{\mathrm{PCl}}_6\right]}^{-}$

2. Fluorination Reaction:
When fluorination occurs in a polar organic solvent, fluorine replaces chlorine atoms preferentially in the anionic species or forms mixed fluoro-chloro complexes while preserving the stable cation [PCl₄]⁺.

3. Formation of Species:
Depending on the extent of fluorination, fluorine exchange yields cationic and anionic complex species containing [PCl₄]⁺ along with fluoro-substituted anions such as [PClF₂]^- and ultimately [PF₆]^-.

Therefore, the species formed during the reaction are:

$[{\mathrm{PCl}}_4{]}^{+}[{\mathrm{PClF}}_2{]}^{-}\text{and}[{\mathrm{PCl}}_4{]}^{+}[{\mathrm{PF}}_6{]}^{-}$