Phosphorus Oxygen Structures: P4O6 and P4O10

Let's understand the structures of phosphorus oxides, specifically P4O6 and P4O10, to determine the number of oxygen atoms bonded to each phosphorus atom.

Both P4O6 and P4O10 have cage-like structures derived from a tetrahedral arrangement of phosphorus atoms.

P4O6 Structure

• The structure of P4O6 can be visualized as four phosphorus atoms ($\text{P}$) forming a tetrahedron.
• Six oxygen atoms ($\text{O}$) are inserted along the edges of this tetrahedron, bridging between each pair of phosphorus atoms.
• Each oxygen atom bridges between two phosphorus atoms.
• In this arrangement, each phosphorus atom is connected to three oxygen atoms. These three oxygen atoms link that phosphorus atom to the other three phosphorus atoms in the structure.

So, in $\text{P}_4\text{O}_6$, each phosphorus centre is bonded to 3 oxygen atoms.

P4O10 Structure

• The structure of P4O10 is based on the P4O6 structure.
• It retains the central P4 tetrahedron with bridging oxygen atoms between phosphorus atoms.
• Additionally, in P4O10, there are four more oxygen atoms compared to P4O6. These four additional oxygen atoms are terminally bonded to each of the four phosphorus atoms.
• Each of these four terminal oxygen atoms is double-bonded to one phosphorus atom.
• Therefore, each phosphorus atom in P4O10 is bonded to three bridging oxygen atoms (single bonds) and one terminal oxygen atom (double bond).

So, in $\text{P}_4\text{O}_{10}$, each phosphorus centre is bonded to a total of 3 bridging oxygen atoms + 1 terminal oxygen atom = 4 oxygen atoms.

Oxygen Atoms Bonded to Phosphorus Summary

Based on the structures:

• In P4O6, each phosphorus atom is bonded to 3 oxygen atoms.
• In P4O10, each phosphorus atom is bonded to 4 oxygen atoms.

The number of oxygen atoms bonded to each phosphorus centre in P4O6 and P4O10 respectively are 3 and 4.