Aluminium phosphide: Difference between revisions

{{distinguish|Aluminium phosphate}}

| Watchedfields = changed

| verifiedrevid = 454459350

| Name = Aluminium phosphide

| ImageFile = File:Aluminum Phosphide.jpg

| ImageSize =

| ImageName = Aluminium phosphide tablets

| ImageFile2 = Sphalerite-unit-cell-depth-fade-3D-balls.png

| ImageSize2 =

| ImageName2 = Crystal structure

| OtherNames = Aluminum phosphide<br />Aluminium(III) phosphide<br />Aluminium monophosphide<br />Phostoxin<br />Fumitoxin

|Section1={{Chembox Identifiers

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| UNNumber = 1397 3048

| SMILES = [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

| CASNo_Ref = {{cascite|correct|CAS}}

| PubChem = 30332

| RTECS = BD1400000

| EINECS = 244-088-0

}}

|Section2={{Chembox Properties

| Formula =

| Al=1 | P=1

| MolarMass = 57.9552 g/mol

| Appearance = Yellow or gray crystals

| Odor = garlic-like

| Density = 2.85 g/cm³

| Solubility = reacts

| MeltingPtC = 2530

| BoilingPt =

| BandGap = 2.5 eV (indirect)<ref name=berger>{{ cite book | author = Berger, L. I. | title = Semiconductor Materials | url = https://archive.org/details/semiconductormat0000berg | url-access = registration | publisher = CRC Press | year = 1996 | isbn = 0-8493-8912-7 | pages = [https://archive.org/details/semiconductormat0000berg/page/125 125] }}</ref>

| RefractIndex = 2.75 (IR), ~3 (Vis) <ref name=berger />

}}

|Section3={{Chembox Structure

| MolShape =

| CrystalStruct = [[Zincblende (crystal structure)|Zincblende]]

| SpaceGroup = [[Cubic_crystal_system#Zincblende_structure|T²_d-F{{overline|4}}3m]]

| LattConst_a = 546.35 pm

| Coordination = [[Tetrahedral]]

| Dipole =

}}

|Section4={{Chembox Thermochemistry

| DeltaHf = -164.4 kJ/mol

| Entropy = 47.3 J/mol K

}}

|Section7={{Chembox Hazards

| ExternalSDS = [http://physchem.ox.ac.uk/MSDS/AL/aluminium_phosphide.html External MSDS]

| FlashPt = >

| FlashPtC = 800

| GHSPictograms = {{GHS02}}{{GHS06}}{{GHS09}}

| GHSSignalWord = Danger

| HPhrases = {{H-phrases|260|300|311|330|400}}

| PPhrases = {{P-phrases|223|231+232|260|264|270|271|273|280|284|301+310|302+352|304+340|310|312|320|321|322|330|335+334|361|363|370+378|391|402+404|403+233|405|501}}

| NFPA-H = 4|NFPA-F = 1|NFPA-R = 2|NFPA-S = W

| LD50 = 11.5 mg/kg

}}

'''Aluminium phosphide''' is a highly toxic [[inorganic compound]] with the chemical formula AlP, used as a wide [[band gap]] semiconductor and a [[fumigant]]. This colorless solid is generally sold as a grey-green-yellow powder due to the presence of impurities arising from [[hydrolysis]] and [[oxidation]].

== Properties ==

AlP crystals are dark grey to dark yellow in color and have a [[Zincblende (crystal structure)|zincblende]] crystal structure<ref>{{ cite web |author1=Van Zeghbroeck |author2=B. J. | title = Bravais Lattices; Zincblende Lattice | publisher = University of Colorado | year = 1997 |url = http://ecee.colorado.edu/~bart/book/bravais.htm }}</ref> with a lattice constant of 5.4510 Å at 300 K.<ref>{{ cite web | title = Lattice Constants | publisher = SiliconFarEast.com | year = 2004 | url = http://www.siliconfareast.com/lattice_constants.htm | access-date = 3 January 2017 }}</ref> They are thermodynamically stable up to {{convert|1000|C}}.<ref name=white />

Aluminium phosphide reacts with [[water]] or acids to release [[phosphine]]:<ref>{{Holleman&Wiberg}}</ref>

:AlP + 3 H₂O → Al(OH)₃ + PH₃

This reaction is the basis of its toxicity.

== Preparation ==

AlP is synthesized by [[combination reaction|combination]] of the elements:<ref name=white>{{ Cite book |author1=White, W. E. |author2=Bushey, A. H. |author3=Holtzclaw, H. F. |author4=Hengeveld, F. W. |chapter=Aluminum Phosphide | editor = Bailar, J. C. | title = Inorganic Syntheses | year = 1953 | volume = 4 | pages = 23–25 | doi = 10.1002/9780470132357.ch7 | isbn = 978-0-470-13235-7 }}</ref><ref name="ref13">{{cite journal|author1=White, W. E. |author2=Bushey, A. H. | title = Aluminum Phosphide – Preparation and Composition | journal = Journal of the American Chemical Society | doi = 10.1021/ja01238a018 | year = 1944 | volume = 66 | issue = 10 | page = 1666 }}</ref>

: 4Al + P₄ → 4AlP

:

Caution must be taken to avoid exposing the AlP to any sources of moisture, as this generates toxic [[phosphine]] gas. Phosphine also poses fire hazards, as it is a dangerous [[pyrophoric]] compound, igniting easily in [[air]].

== Uses ==

=== Pesticide ===

AlP is used as a [[rodenticide]], [[insecticide]], and [[fumigant]] for stored cereal grains. It is used to kill small verminous [[mammal]]s such as [[mole (animal)|moles]] and [[rodent]]s. 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 [[Combustion|ignition]] or [[explosion]] of the phosphine gas.<ref>United States Environmental Protection Agency. (2006). ''Inert Reassessment-Ammonium Carbamate'' [Data File]. Retrieved from http://www.epa.gov/opprd001/inerts/carbamate.pdf</ref>

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.<ref name="ref13" />

: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.<ref>{{Ullmanns|author = Buckle, A.|title = Rodenticides|doi = 10.1002/14356007.a23_211}}</ref>

=== Semiconductor applications ===

Industrially, AlP is a [[semiconductor material]] that is usually [[alloy]]ed with other binary materials for applications in devices such as [[light-emitting diode]]s (e.g. [[aluminium gallium indium phosphide]]).<ref>{{ cite book | author = Corbridge, D. E. C. | title = Phosphorus: An Outline of its Chemistry, Biochemistry, and Technology | edition = 5th | publisher = Elsevier | location = Amsterdam | year = 1995 | isbn = 0-444-89307-5 }}</ref>

== Toxicology ==

{{Main|Aluminium phosphide poisoning}}

Highly poisonous, aluminium phosphide has been used for suicide.<ref>{{cite news |date=2002-10-10 |title=Millionaire's death sparks poison scare |work=[[BBC News]] |url=http://news.bbc.co.uk/2/hi/uk_news/england/2314911.stm |url-status=live |access-date=2009-04-05 |archive-url=https://web.archive.org/web/20120406051135/http://news.bbc.co.uk/2/hi/uk_news/england/2314911.stm |archive-date=2012-04-06}}</ref> Fumigation has also caused unintentional deaths.<ref>{{cite news |title = Fumes kill two Danes in Jeddah |work = [[BBC News]] |date = 2009-02-24 |url = http://news.bbc.co.uk/2/hi/middle_east/7908102.stm |access-date = 2009-02-25| archive-url= https://web.archive.org/web/20090225112450/http://news.bbc.co.uk/2/hi/middle_east/7908102.stm| archive-date= 25 February 2009 | url-status= live}}</ref><ref>{{cite news |title = Family loses 2nd child in suspected pesticide poisoning |publisher = [[KSL-TV]] |url = http://www.ksl.com/?nid=148&sid=9629232 |date = 2010-02-09| archive-url= https://web.archive.org/web/20100211133556/http://www.ksl.com/?nid=148&sid=9629232| archive-date= 11 February 2010 | url-status= live}}</ref><ref>{{cite news |title = 4 children dead in Texas in pesticide spraying incident |work= [[CBS News]] |date=2017-01-02 |url=http://www.cbsnews.com/news/gas-poisoning-amarillo-texas-four-children-dead-others-injured/}}</ref> 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.<ref>{{Cite journal| last1 = Shadnia | first1 = S.| last2 = Sasanian | first2 = G.| last3 = Allami | first3 = P.| last4 = Hosseini | first4 = A.| last5 = Ranjbar | first5 = A.| last6 = Amini-Shirazi | first6 = N.| last7 = Abdollahi | first7 = M. |display-authors=3| doi = 10.1177/0960327108097194| title = A Retrospective 7-Years Study of Aluminum Phosphide Poisoning in Tehran: Opportunities for Prevention| journal = Human & Experimental Toxicology| volume = 28| issue = 4| pages = 209–213| year = 2009| pmid = 19734272| bibcode = 2009HETox..28..209S| s2cid = 38361878}}</ref><ref>{{ cite journal | last1 = Mehrpour | first1 = O. | last2 = Singh | first2 = S. | title = Rice Tablet Poisoning: A Major Concern in Iranian Population | journal = Human & Experimental Toxicology | volume = 29 | issue = 8 | pages = 701–702 | year = 2010 | pmid = 20097728 | doi = 10.1177/0960327109359643 | bibcode = 2010HETox..29..701M | s2cid = 37380994 }}</ref>

Recycling of used aluminium phosphide containers caused the death of three family members in [[Alcalá de Guadaira|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.<ref>{{cite news|title=La familia de Alcalá de Guadaira murió tras inhalar plaguicida|url=http://www.lavanguardia.com/local/sevilla/20140203/54400796210/la-familia-de-alcala-de-guadaira-murio-tras-inhalar-fosfina-de-unos-tapones.html|access-date=3 February 2014|newspaper=[[La Vanguardia]]|date=3 February 2014|agency=[[Agencia EFE]]}}</ref>

Aluminium phosphide poisoning is considered a wide-scale problem in the Indian subcontinent.<ref name=r4>{{cite journal|pmid=8773034|year=1995|last1=Siwach|first1=SB|last2=Gupta|first2=A|title=The profile of acute poisonings in Harayana-Rohtak Study|volume=43|issue=11|pages=756–9|journal=The Journal of the Association of Physicians of India}}</ref><ref>{{cite journal|pmid=10414665|year=1999|last1=Singh|first1=D|last2=Jit|first2=I|last3=Tyagi|first3=S|title=Changing trends in acute poisoning in Chandigarh zone: A 25-year autopsy experience from a tertiary care hospital in northern India|volume=20|issue=2|pages=203–10|journal=The American Journal of Forensic Medicine and Pathology|doi=10.1097/00000433-199906000-00019}}</ref>

== References ==

{{reflist|colwidth=35em}}

{{phosphides}}

{{Authority control}}

[[Category:III-V semiconductors]]

[[Category:Zincblende crystal structure]]