# Hybridisation of POCl3 [duplicate]

I was doing lewis structures and i came across a question asking the structure of POCl3. Here, the answer is a tetrahedral shape with P as central atom connected to 3Cl atoms by a single bond and 1 oxygen atom by a double bond. The valency of P is 3. So, it needs 3 electrons to get the nobel gas configuration and become stable so it could have formed single bonds with 2 cl atoms and single bond with an oxygen atom which would be single bonded to cl atom. Why isn't this structure correct?

And how can P form 4 bonds while it needs only 3? I think it's something related to D-orbital but if it undergoes sp3d hybridisation, it would need 5 bonds. Also, the structure of this compound is tetrahedral and hybridisation of P is sp3. How can this be? How can it form 4 bonds although it has only 3 unpaired electrons? Nitrogen couldn't form such compounds.

I googled about it and could find nothing but the hybridisation and lewis structure. My actual question isn't answered anywhere

## marked as duplicate by Mithoron, pentavalentcarbon, Todd Minehardt, airhuff, JanOct 1 '17 at 14:39

• Think of it as $\ce{[POCl2]+[Cl]-}$. Still a wrong picture, though. You'd need resonance. – DHMO Jan 15 '17 at 14:56
• There should be a duplicate lying around here somewhere … Basically, don’t use d orbitals unless your at school and your teacher tells you to. And if that is the case, forget it the moment you leave school. Instead, you can think of $\ce{\overset{+}{P}-\overset{-}{O}}$, i.e. charge separation. Also, @DHMO’s description is wrong in this case; charge separation is a more simple and better description. 4e3c bonds are only required for pentacoordinated phosphorus atoms. – Jan Jan 15 '17 at 22:27