Zinc diphosphide

Zinc diphosphide (ZnP₂) is an inorganic chemical compound. It is a red semiconductor solid with a band gap of 2.1 eV.^[2] It is one of the two compounds in the zinc-phosphorus system, the other being zinc phosphide (Zn₃P₂).

Zinc diphosphide

Identifiers
CAS Number	12037-79-5
3D model (JSmol)	Interactive image
ChemSpider	141421
EC Number	234-867-3
InChI InChI=1S/P2.Zn/c1-2;/q-2;+2 Key: WHCVAYNMVBDLCU-UHFFFAOYSA-N
SMILES [P-]=[P-].[Zn+2]
Properties
Chemical formula	ZnP2
Molar mass	127.33 g/mol
Appearance	red crystals
Density	3.53 g/cm3
Melting point	1,040 °C (1,900 °F; 1,310 K)
Structure
Crystal structure	Tetragonal, tP24
Space group	P41212, No. 92[1]
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Synthesis and reactions

Zinc diphosphide can be prepared by the reaction of zinc with phosphorus.

2 Zn + P₄ → 2 ZnP₂

Structure

ZnP₂ has a room-temperature tetragonal form that converts to a monoclinic form at around 990 °C.^[3] In both of these forms, there are chains of P atoms, helical in the tetragonal, semi-spiral in the monoclinic.^[4]

This compound is part of the Zn-Cd-P-As quaternary system and exhibit partial solid-solution with other binary compounds of the system.^[5]

Safety

ZnP₂, like Zn₃P₂, is highly toxic due to the release of phosphine gas when the material reacts with gastric acid.

References

1. Litvinchuk, A. P.; Valakh, M. Ya. (2020). "Raman and infrared phonons in tetragonal ZnP2 and CdP2 crystals: A density functional study". Journal of Physics: Condensed Matter. 32 (44): 445401. Bibcode:2020JPCM...32R5401L. doi:10.1088/1361-648X/aba720. PMID 32679574. S2CID 220629594.
2. Hegyi, I. J.; Loebner, E. E.; Poor (Jr.), E. W.; White, J. G. (1963). "Two crystal forms of ZnP2, their preparation, structure, and optoelectronic properties". Journal of Physics and Chemistry of Solids. 24 (2): 333–337. Bibcode:1963JPCS...24..333H. doi:10.1016/0022-3697(63)90140-9.
3. Ghasemi, M.; Stutz, E. Z.; Escobar Steinvall, S.; Zamani, M.; Fontcuberta i Morral, A. (2019). "Thermodynamic re-assessment of the Zn–P binary system". Materialia. 6: 100301. doi:10.1016/j.mtla.2019.100301. S2CID 140792691.
4. Hans Georg von Schnering and Wolfgang Hönle, 1994, Phosphides: Solid State Chemistry, Encyclopedia of Inorganic chemistry, Ed. R Bruce King, John Wiley and Sons, ISBN 0-471-93620-0
5. Trukhan, V. M.; Izotov, A. D.; Shoukavaya, T. V. (2014). "Compounds and solid solutions of the Zn-Cd-P-As system in semiconductor electronics". Inorganic Materials. 50 (9): 868–873. doi:10.1134/S0020168514090143. S2CID 94409384.