Yes, the compound P2F4 does exhibit an expanded octet.
Don't know P2I5. PI5 (phosphorus pentaiodide) is more likely but couldn't find anything on that. Maybe this is meant: P2I4 , diphosphorus tetraiodide synthesized from phosphorus triiodide 2 PI3 → P2I4 + I2
This compound probable doesn't exist.
The formula for Phosphorus Trifluoride is PF3
Don't know P2I5. PI5 (phosphorus pentaiodide) is more likely but couldn't find anything on that. Maybe this is meant: P2I4 , diphosphorus tetraiodide synthesized from phosphorus triiodide 2 PI3 → P2I4 + I2
This compound probable doesn't exist.
The formula for Phosphorus Trifluoride is PF3