Aluminium phosphide

Source: Wikipedia, the free encyclopedia.
Not to be confused with Aluminium phosphate.
Aluminium phosphide
Aluminium phosphide tablets
Crystal structure
Names
Other names
Aluminum phosphide
Aluminium(III) phosphide
Aluminium monophosphide
Phostoxin
Fumitoxin
Identifiers
3D model (
JSmol
)
ChemSpider
ECHA InfoCard
 100.040.065 Edit this at Wikidata
EC Number
  • 244-088-0
RTECS number
  • BD1400000
UNII
UN number 1397 3048
  • InChI=1S/Al.P checkY
    Key: PPNXXZIBFHTHDM-UHFFFAOYSA-N checkY
  • InChI=1/Al.P/rAlP/c1-2
    Key: PPNXXZIBFHTHDM-LQQCNYPFAR
  • [PH+]12[Al-][PH+]3[Al-][PH+]([AlH-]14)[AlH-]1[P+]5([AlH-]38)[Al-]26[PH+]2[AlH-]([P+]4)[PH+]1[Al-][PH+]3[AlH-]2[P+][AlH-]([PH+]6[AlH-]([PH+])[PH+]68)[PH+]([Al-]6)[AlH-]35
Properties
AlP
Molar mass 57.9552 g/mol
Appearance Yellow or gray crystals
Odor garlic-like
Density 2.85 g/cm3
Melting point 2,530 °C (4,590 °F; 2,800 K)
reacts
Band gap 2.5 eV (indirect)[1]
2.75 (IR), ~3 (Vis) [1]
Structure
Zincblende
T2d-F43m
a = 546.35 pm
Tetrahedral
Thermochemistry
47.3 J/mol K
Std enthalpy of
formation
(ΔfH⦵298)
 -164.4 kJ/mol
Hazards
GHS labelling:
GHS02: FlammableGHS06: ToxicGHS09: Environmental hazard
Danger
H260, H300, H311, H330, H400
P223, P231+P232, P260, P264, P270, P271, P273, P280, P284, P301+P310, P302+P352, P304+P340, P310, P312, P320, P321, P322, P330, P335+P334, P361, P363, P370+P378, P391, P402+P404, P403+P233, P405, P501
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth 4: Very short exposure could cause death or major residual injury. E.g. VX gasFlammability 1: Must be pre-heated before ignition can occur. Flash point over 93 °C (200 °F). E.g. canola oilInstability 2: Undergoes violent chemical change at elevated temperatures and pressures, reacts violently with water, or may form explosive mixtures with water. E.g. white phosphorusSpecial hazard W: Reacts with water in an unusual or dangerous manner. E.g. sodium, sulfuric acid
4
1
2
W
Flash point > 800 °C (1,470 °F; 1,070 K)
Lethal dose or concentration (LD, LC):
11.5 mg/kg
Safety data sheet (SDS) External MSDS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

Aluminium phosphide is a highly toxic

oxidation
.

Properties

AlP crystals are dark grey to dark yellow in color and have a

zincblende crystal structure[2] with a lattice constant of 5.4510 Å at 300 K.[3] They are thermodynamically stable up to 1,000 °C (1,830 °F).[4]

Aluminium phosphide reacts with water or acids to release phosphine:[5]

AlP + 3 H2O → Al(OH)3 + PH3
AlP + 3 H+ → Al3+ + PH3

This reaction is the basis of its toxicity.

Preparation

AlP is synthesized by combination of the elements:[4][6]

4Al + P4 → 4AlP

Caution must be taken to avoid exposing the AlP to any sources of moisture, as this generates toxic

air
.

Uses

Pesticide

AlP is used as a

fumigant for stored cereal grains. It is used to kill small verminous mammals such as moles and rodents. The tablets or pellets, known as "wheat pills", typically also contain other chemicals that evolve ammonia and carbon dioxide (e.g. ammonium carbamate), which help to reduce the potential for spontaneous ignition or explosion of the phosphine gas.[7]

AlP is used as both a fumigant and an oral pesticide. As a rodenticide, aluminium phosphide pellets are provided as a mixture with food for consumption by the rodents. The acid in the digestive system of the rodent reacts with the phosphide to generate the toxic phosphine gas. Other pesticides similar to aluminium phosphide are zinc phosphide and calcium phosphide. In this application, aluminium phosphide can be encountered under various brand names, e.g. PestPhos,Quickphos, Celphos, Fostox, Fumitoxin, Phostek, Phostoxin, Talunex, Fieldphos, and Weevil-Cide. It generates phosphine gas according to the following hydrolysis equation.[6]

2 AlP + 6 H2O → Al2O3∙3 H2O + 2 PH3

It is used as a fumigant when other pesticide applications are impractical and when structures and installations are being treated, such as in ships, aircraft, and grain silos. All of these structures can be effectively sealed or enclosed in a gastight membrane, thereby containing and concentrating the phosphine fumes. Fumigants are also applied directly to rodent burrows.[8]

Semiconductor applications

Industrially, AlP is a

semiconductor material that is usually alloyed with other binary materials for applications in devices such as light-emitting diodes (e.g. aluminium gallium indium phosphide).[9]

Toxicology

Main article: Aluminium phosphide poisoning

Highly poisonous, aluminium phosphide has been used for suicide.[10] Fumigation has also caused unintentional deaths.[11][12][13] Known as "rice tablet" in Iran, for its use to preserve rice, there have been frequent incidents of accidental or intentional death. There is a campaign by the Iranian Forensic Medicine Organization to stop its use as a pesticide.[14][15]

Recycling of used aluminium phosphide containers caused the death of three family members in

Alcalá de Guadaira, Spain. They had been keeping them in plastic sacks in their bathroom. The deaths occurred accidentally due to aluminium phosphide reacting with water or moisture, and becoming phosphine, leading to their death within hours.[16]

Aluminium phosphide poisoning is considered a wide-scale problem in the Indian subcontinent.[17][18]

References

  1. ^
    ISBN 0-8493-8912-7
    .
  2. ^ Van Zeghbroeck; B. J. (1997). "Bravais Lattices; Zincblende Lattice". University of Colorado.
  3. ^ "Lattice Constants". SiliconFarEast.com. 2004. Retrieved 3 January 2017.
  4. ^
    ISBN 978-0-470-13235-7
    .
  5. ISBN 0-12-352651-5
  6. ^
    doi:10.1021/ja01238a018
    .
  7. ^ United States Environmental Protection Agency. (2006). Inert Reassessment-Ammonium Carbamate [Data File]. Retrieved from http://www.epa.gov/opprd001/inerts/carbamate.pdf
  8. ISBN 978-3527306732
    .
  9. ISBN 0-444-89307-5
    .
  10. ^ "Millionaire's death sparks poison scare". BBC News. 2002-10-10. Archived from the original on 2012-04-06. Retrieved 2009-04-05.
  11. ^ "Fumes kill two Danes in Jeddah". BBC News. 2009-02-24. Archived from the original on 25 February 2009. Retrieved 2009-02-25.
  12. ^ "Family loses 2nd child in suspected pesticide poisoning". KSL-TV. 2010-02-09. Archived from the original on 11 February 2010.
  13. ^ "4 children dead in Texas in pesticide spraying incident". CBS News. 2017-01-02.
  14. S2CID 38361878
    .
  15. S2CID 37380994
    .
  16. Agencia EFE
    . 3 February 2014. Retrieved 3 February 2014.
  17. PMID 8773034
    .
  18. PMID 10414665
    .
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