Difference between revisions of "Phosphoryl chloride"
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:6 PCl<sub>5</sub> + P<sub>4</sub>O<sub>10</sub> → 10 POCl<sub>3</sub> | :6 PCl<sub>5</sub> + P<sub>4</sub>O<sub>10</sub> → 10 POCl<sub>3</sub> | ||
| − | Heating [[sodium chloride]] with phosphorus pentoxide will also give phosphorus oxychloride | + | Heating [[sodium chloride]] with phosphorus pentoxide will also give phosphorus oxychloride: |
| − | Reduction of tricalcium phosphate with [[carbon]] in the presence of [[chlorine]] gas is more accessible route, although it requires high temperatures. | + | :2 P<sub>2</sub>O<sub>5</sub> + 3 NaCl → 3 NaPO<sub>3</sub> + POCl<sub>3</sub> |
| + | |||
| + | Reduction of tricalcium phosphate with [[carbon]] in the presence of [[chlorine]] gas is more accessible route, although it requires high temperatures. It should be noted that chlorine and carbon monoxide can form very toxic [[phosgene]]. | ||
:Ca<sub>3</sub>(PO<sub>4</sub>)<sub>2</sub> + 6 C + 6 Cl<sub>2</sub> → 2 POCl<sub>3</sub> + 3 CaCl<sub>2</sub> + 6 CO | :Ca<sub>3</sub>(PO<sub>4</sub>)<sub>2</sub> + 6 C + 6 Cl<sub>2</sub> → 2 POCl<sub>3</sub> + 3 CaCl<sub>2</sub> + 6 CO | ||
Revision as of 09:43, 15 August 2022
| Names | |
|---|---|
| IUPAC name
Phosphoryl trichloride
| |
| Other names
Phosphorus oxychloride
Phosphoric trichloride Phosphorus trichloride oxide Phosphorous(V) oxychloride Trichlorophosphate | |
| Properties | |
| POCl3 | |
| Molar mass | 153.33 g/mol |
| Appearance | Colorless fuming liquid |
| Odor | Pungent, acidic |
| Density | 1.645 g/cm3 |
| Melting point | 1.25 °C (34.25 °F; 274.40 K) |
| Boiling point | 105.8 °C (222.4 °F; 378.9 K) |
| Reacts | |
| Solubility | Reacts with alcohols, carboxylic acids Soluble in benzoyl chloride, bromine, bromoacetic acid, carbon disulfide, liq. Cl2, liq. HBr, liq. HCl, hydrogen cyanide, liq. H2S, anh. nitric acid, sulfuryl chloride, liq. SO2, SnCl4 Sparingly soluble in liq. HI |
| Vapor pressure | 40 mmHg (27.3 °C) |
| Thermochemistry | |
| Std enthalpy of
formation (ΔfH |
-615.7 kJ/mol |
| Hazards | |
| Safety data sheet | Sigma-Aldrich |
| Flash point | Non-flammable |
| Related compounds | |
| Related compounds
|
Phosphoryl bromide |
| Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
Phosphoryl chloride or phosphorus oxychloride is a fuming colourless liquid, widely used for the synthesis of phosphate esters. It is a colorless fuming liquid, with the formula POCl3.
Contents
Properties
Chemical
Phosphorus oxychloride reacts with water to form phosphoric acid and hydrogen chloride fumes.
- POCl3 + 3 H2O → H3PO4 + 3 HCl
Physical
Phosphoryl chloride is a colorless liquid which fumes in air.
Availability
Is sold by big chemical suppliers, but it's next to impossible to get hold of.
Phosphoryl chloride is listed on Schedule 3 of the Chemical Weapons Convention. Transactions tend to be monitored, especially if large amounts are done.
Preparation
Phosphoryl chloride can be prepared by oxidizing phosphorus trichloride with pure oxygen, between 20-50 °C. Air is ineffective for this reaction.
- 2 PCl3 + O2 → 2 POCl3
Potassium chlorate can also be used as oxidizer, instead of pure oxygen.
Reaction of phosphorus pentachloride with phosphorus pentoxide will also give POCl3:
- 6 PCl5 + P4O10 → 10 POCl3
Heating sodium chloride with phosphorus pentoxide will also give phosphorus oxychloride:
- 2 P2O5 + 3 NaCl → 3 NaPO3 + POCl3
Reduction of tricalcium phosphate with carbon in the presence of chlorine gas is more accessible route, although it requires high temperatures. It should be noted that chlorine and carbon monoxide can form very toxic phosgene.
- Ca3(PO4)2 + 6 C + 6 Cl2 → 2 POCl3 + 3 CaCl2 + 6 CO
Projects
- Make phosphate esters
- Make nitriles from amides
- Vilsmeier–Haack reaction
Handling
Safety
Phosphorus oxychloride is very corrosive and toxic. Wear proper protection when handling the compound. Only work in a fumehood or in a well ventilated place.
Storage
Phosphoryl chloride should be stored in Schlenk flasks, as they're the best storage containers for air and water sensitive reagents.
Disposal
Phosphoryl chloride should be neutralized with a base, such as calcium hydroxide suspension outside or in a well ventilated area. Always add small amounts of POCl3 to prevent splashing. Try not to use carbonates, as they will fizzle and cause some POCl3 to become airborne. Since small amounts of HCl fumes will be formed anyway, use a lidded container in case of runaway.
References
Relevant Sciencemadness threads
- Articles containing unverified chemical infoboxes
- Chembox articles without image
- Chemical compounds
- Inorganic compounds
- Phosphorus compounds
- Chlorine compounds
- Phosphorus halides
- Oxohalides
- Materials that react with water
- Materials unstable in basic solution
- Things that can kill you very quickly
- Things that should NOT be messed with except by professionals
- Choking agents
- Schedule 3 chemicals
- Liquids
