Question

Consider the molecules/ions: $BC{l}_3,S{F}_4,N{F}_3,P{F}_3,N(Si{H}_3{)}_3,Cl{O}_3^{+},Xe{O}_4,XeO{F}_2,SOC{l}_2$.
The number of molecules/ions among the above which contain $p\pi -d\pi$ bonds is:

Answer 1

$S{F}_4$ has see-saw shape but has no $p\pi -d\pi$ bonds.

In $N{F}_3$ both atoms do not have $d$ orbital, hence no $p\pi -d\pi$ bonds.

Six molecules/ions namely, $P{F}_3,N(Si{H}_3{)}_3,Cl{O}_3^{+},Xe{O}_4,XeO{F}_2$ and $SOC{l}_2$ contain $p\pi -d\pi$ bonds.

$BC{l}_3$ has only $p\pi -p\pi$ bonds no $p\pi -d\pi$ bonds.