Phosphorus sesquisulfide

P4S3
IUPAC name tetraphosphorus trisulfide or 3,5,7-trithia-1,2,4,6-tetraphosphatricyclo[2.2.1.01,6]heptane
Other names phosphorus trisulfide, phosphorus sesquisulfide, phosphorus sulfide
Identifiers
CAS number	1314-85-8
PubChem	14818
ChemSpider	14134 Y
RTECS number	TH4330000
Jmol-3D images	Image 1
SMILES S1P2P3SP1SP23
InChI InChI=1S/P4S3/c5-1-2-3(1)7-4(5)6-2 Y Key: RWQFRHVDPXXRQN-UHFFFAOYSA-N Y InChI=1/P4S3/c5-1-2-3(1)7-4(5)6-2 Key: RWQFRHVDPXXRQN-UHFFFAOYAM
Properties
Molecular formula	P4S3
Molar mass	220.093 g/mol
Appearance	yellow, yellow-green or gray solid
Density	2.08 g.cm3,[1] solid
Melting point	172.5 °C
Boiling point	408 °C
Y (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Phosphorus sesquisulfide is the inorganic compound with the formula P₄S₃. This yellow solid is one of two commercially produced phosphorus sulfides. It is a component of "strike anywhere" matches.

Depending on purity, samples can appear yellow-green to grey. The compound was discovered by G. Lemoine and first produced safely in commercial quantities in 1898 by Albright and Wilson. It dissolves in an equal weight of carbon disulfide (CS₂). Unlike some other phosphorus sulfides, P₄S₃ is slow to hydrolyze and has a well-defined melting point.

Structure and synthesis

The molecule has C_3v symmetry. It is a derivative of the tetrahedral (P₄) unit from insertion of sulfur into three P-P bonds. The P-S and P-P distances are 2.090 and 2.235 Å, respectively. P₄Se₃ and P₄S₃ adopt the same structures.^[1]

P₄S₃ is produced by the reaction of red or white phosphorus with sulfur. Excess sulfur gives phosphorus pentasulfide (P₄S₁₀). It is estimated that 150 ton/y were produced in 1989.^[2]

Applications

A 1:2 mixture of P₄S₃ and potassium chlorate, together with other materials, comprises the heads of "strike-anywhere matches".^[3]

Safety

Its flash point is about 100 °C.

References

1. ^ ^{a b} Leung, Y. C.; Waser, J.; van Houten, S.; Vos, A.; Wiegers, G. A.; Wiebenga, E. H. “The crystal structure of P₄S₃”. Acta Crystallographica , Volume 10, pages 574-582, year 1957. DOI:10.1107/S0365110X57002042
2. ^ Gerhard Bettermann, Werner Krause, Gerhard Riess, Thomas Hofmann “Phosphorus Compounds, Inorganic” in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim. doi: 10.1002/14356007.a19_527
3. ^ D. E. C. Corbridge. Phosphorus: An Outline of its Chemistry, Biochemistry, and Technology. 5th Edition. Elsevier: Amsterdam 1995. ISBN 0-444-89307-5. For a discussion of safety matches, see pages 115-116.