Octachlorotetraphosphazene

Octachlorotetraphosphazene is an inorganic compound with the formula (NPCl2)4. The molecule has a cyclic, unsaturated backbone consisting of alternating phosphorus and nitrogen centers, and can be viewed as a tetramer of the hypothetical compound N≡PCl2.

Octachlorotetraphosphazene
Octachlorotetraphosphazene structure (ball-and-stick)
Octachlorotetraphosphazene structure (ball-and-stick)
Names
IUPAC name
2,2,4,4,6,6,8,8-Octachloro-1,3,5,7,2λ5,4λ5,6λ5,8λ5-tetrazatetraphosphocine
Other names
Phosphonitrilic chloride tetramer
Octachlorocyclotetraphosphazene
Tetraphosphonitrilic chloride
2,2,4,4,6,6,8,8-octachloro-2,2,4,4,6,6,8,8-octahydro-1,3,5,7,2,4,6,8-tetraazatetraphosphocine
2,2,4,4,6,6,8,8-octachloro-1,3,5,7-tetraza-2λ5,4λ5,6λ5,8λ5-tetraphosphacycloocta-1,3,5,7-tetraene
Identifiers
3D model (JSmol)
ChEMBL
ChemSpider
EC Number
  • 220-972-1
  • InChI=1S/Cl8N4P4/c1-13(2)9-14(3,4)11-16(7,8)12-15(5,6)10-13
    Key: PEJQKHLWXHKKGS-UHFFFAOYSA-N
  • N1=P(N=P(N=P(N=P1(Cl)Cl)(Cl)Cl)(Cl)Cl)(Cl)Cl
Properties
N4Cl8P4
Molar mass 463.55 g/mol
Appearance Colorless solid
Density 2.27 g/mL at -173 °C
Melting point 123 to 124 °C (253 to 255 °F; 396 to 397 K)
Boiling point 188 °C at 15 Torr
Decomposes
Solubility in hexane 7.0 g/100g (20 °C)
Solubility in toluene 1.8 g/100g (20 °C)
Solubility in CCl4 1.6 g/100g (20 °C)
1.675 (589 nm)
Structure
Tetragonal
86
D4h
0.39 D
Thermochemistry
-1084.9 kJ·mol−1
64.9 kJ·mol−1 (325 °C)
95.9–97.5 kJ·mol−1
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
Mild irritant
GHS labelling:
GHS05: Corrosive
Danger
H314
P260, P280, P304+P340, P305+P351+P338, P363
Flash point Non-flammable
Related compounds
Related compounds
Hexachlorophosphazene
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

The compound has not been studied as much as the related species hexachlorotriphosphazene, in the samples of which octachlorotetraphosphazene is usually found as an unwanted contamintant.[1]

Structure and bonding

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Octachlorotetraphosphazene has a P4N4 core with six equivalent P–N bonds.[2]

Synthesis

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NH4Cl + PCl5 → 1/n (NPCl2)n + HCl

Reactions

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Substitution at P

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Some spiro-, ansa-, and spiro-ansa-cyclic derivatives have been prepared via nucleophilic substitution of octachlorotetraphosphazene with alkoxides.[3]

References

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  1. ^ Allcock, H. R. (1972). Phosphorus-nitrogen compounds ; cyclic, linear, and high polymeric systems. New York: Academic Press. ISBN 978-0-323-14751-4. OCLC 838102247.
  2. ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.
  3. ^ Ture, Sedat (2016-01-02). "Synthesis and characterization of spiro-, ansa-, and spiro-ansa-cyclic derivatives of cyclotetraphosphazene with the reactions of pentane-1,5-diol". Phosphorus, Sulfur, and Silicon and the Related Elements. 191 (1): 129–139. doi:10.1080/10426507.2015.1054483.