Phosphine#Primary phosphines

{{About|{{chem2|PH3}}|organic derivatives| Organophosphine |the visual phenomenon|phosphene|the star|Kepler-289}}

{{chembox

| verifiedrevid = 464205019

| ImageFile1 = Phosphine.png

| ImageName1 = Skeletal formula of phosphine

| ImageClass1 = skin-invert

| ImageFileL1 = Phosphine-3D-balls.png

| ImageNameL1 = Ball-and-stick model of phosphine

| ImageFileR1 = Phosphine-underside-3D-vdW.png

| ImageNameR1 = Spacefill model of phosphine

| ImageCaptionR1 = {{legend|orange|Phosphorus, P}}{{legend|white|Hydrogen, H}}

| IUPACName = Phosphane

| OtherNames = Hydrogen phosphide
Phosphamine
Phosphorus trihydride
Phosphorated hydrogen

|Section1={{Chembox Identifiers

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

| ChemSpiderID = 22814

| InChI = 1/H3P/h1H3

| InChIKey = XYFCBTPGUUZFHI-UHFFFAOYAP

| ChEBI_Ref = {{ebicite|correct|EBI}}

| ChEBI = 30278

| SMILES = P

| StdInChI_Ref = {{stdinchicite|correct|chemspider}}

| StdInChI = 1S/H3P/h1H3

| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}

| StdInChIKey = XYFCBTPGUUZFHI-UHFFFAOYSA-N

| CASNo = 7803-51-2

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

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = FW6947296I

| PubChem = 24404

| EINECS = 232-260-8

| UNNumber = 2199

| RTECS = SY7525000

| Gmelin = 287

}}

|Section2={{Chembox Properties

| Formula = {{chem2|PH3}}

| MolarMass = 33.99758{{nbsp}}g/mol

| Appearance = Colourless gas

| Odor = odorless as pure compound; fish-like or garlic-like commercially

| Density = 1.379{{nbsp}}g/L, gas (25{{nbsp}}°C)

| Solubility = 31.2{{nbsp}}mg/100{{thinsp}}ml (17{{nbsp}}°C)

| SolubleOther = Soluble in alcohol, ether, {{chem2|CS2|link=Carbon disulfide}}
slightly soluble in benzene, chloroform, ethanol

| MeltingPtC = -132.8

| BoilingPtC = -87.7

| Viscosity = 1.1×10⁻⁵{{nbsp}}Pa⋅s

| VaporPressure = 41.3{{nbsp}}atm (20{{nbsp}}°C)

| RefractIndex = 2.144

| ConjugateAcid = Phosphonium ({{Chem2|PH4+}})

}}

|Section3={{Chembox Structure

| MolShape = Trigonal pyramidal

| Dipole = 0.58{{nbsp}}D

}}

|Section4={{Chembox Thermochemistry

| DeltaHf = 5{{nbsp}}kJ/mol{{cite book| last= Zumdahl |first=Steven S.|title =Chemical Principles |edition=6th | publisher = Houghton Mifflin | year = 2009| isbn = 978-0-618-94690-7|page=A22}}

| Entropy = 210{{nbsp}}J/mol⋅K

| HeatCapacity = 37{{nbsp}}J/mol⋅K

| DeltaGf = 13{{nbsp}}kJ/mol

}}

|Section7={{Chembox Hazards

| ExternalSDS = [http://www.inchem.org/documents/icsc/icsc/eics0694.htm ICSC 0694]

| GHSPictograms = {{GHS02}} {{GHS06}} {{GHS05}} {{GHS09}}

| HPhrases =

| PPhrases =

| NFPA-H = 4

| NFPA-F = 4

| NFPA-R = 2

| FlashPt = Flammable gas

| AutoignitionPtC = 38

| AutoignitionPt_notes = (see text)

| ExploLimits = 1.79–98%

| IDLH = 50{{nbsp}}ppm{{PGCH|0505}}

| LD50 = 3.03{{nbsp}}mg/kg (rat, oral)

| LC50 = 11{{nbsp}}ppm (rat, 4{{nbsp}}hr){{IDLH|7803512|Phosphine}}

| REL = TWA 0.3{{nbsp}}ppm (0.4{{nbsp}}mg/m³), ST 1{{nbsp}}ppm (1{{nbsp}}mg/m³)

| PEL = TWA 0.3{{nbsp}}ppm (0.4{{nbsp}}mg/m³)

| LCLo = 1000{{nbsp}}ppm (mammal, 5{{nbsp}}min)
270{{nbsp}}ppm (mouse, 2{{nbsp}}hr)
100{{nbsp}}ppm (guinea pig, 4{{nbsp}}hr)
50{{nbsp}}ppm (cat, 2{{nbsp}}hr)
2500{{nbsp}}ppm (rabbit, 20{{nbsp}}min)
1000{{nbsp}}ppm (human, 5{{nbsp}}min)

}}

|Section8={{Chembox Related

| OtherCations = {{ubl|Ammonia|Arsine|Stibine|Bismuthine}}

| OtherCompounds = {{ubl|Trimethylphosphine|Triphenylphosphine}}

}}

Phosphine (IUPAC name: phosphane) is a colorless, flammable, highly toxic compound with the chemical formula {{chem2|PH3|auto=yes}}, classed as a pnictogen hydride. Pure phosphine is odorless, but technical grade samples have a highly unpleasant odor like rotting fish, due to the presence of substituted phosphine and diphosphane ({{chem2|P2H4}}). With traces of {{chem2|P2H4}} present, {{chem2|PH3}} is spontaneously flammable in air (pyrophoric), burning with a luminous flame. Phosphine is a highly toxic respiratory poison, and is immediately dangerous to life or health at 50 ppm. Phosphine has a trigonal pyramidal structure.

Phosphines are compounds that include {{chem2|PH3}} and the organophosphines, which are derived from {{chem2|PH3}} by substituting one or more hydrogen atoms with organic groups.{{GoldBookRef|title=phosphines|file=P04553}} They have the general formula {{chem2|PH_{3−n}R_{n}|}}. Phosphanes are saturated phosphorus hydrides of the form {{chem2|P_{n}H_{n+2} }}, such as triphosphane.{{GoldBookRef|title=phosphanes|file=P04548}} Phosphine ({{chem2|PH3}}) is the smallest of the phosphines and the smallest of the phosphanes.

History

Philippe Gengembre (1764–1838), a student of Lavoisier, first obtained phosphine in 1783 by heating white phosphorus in an aqueous solution of potash (potassium carbonate).Gengembre (1783) [https://archive.org/stream/mmoiresdemath10acad#page/651/mode/1up "Mémoire sur un nouveau gas obtenu, par l'action des substances alkalines, sur le phosphore de Kunckel"] (Memoir on a new gas obtained by the action of alkaline substances on Kunckel's phosphorus), Mémoires de mathématique et de physique, 10 : 651–658.For further information about the early history of phosphine, see:

The Encyclopædia Britannica (1911 edition), vol. 21, p. 480: [https://books.google.com/books?id=Wto9AQAAMAAJ&pg=PA480 Phosphorus: Phosphine.] {{Webarchive|url=https://web.archive.org/web/20151104205338/https://books.google.com/books?id=Wto9AQAAMAAJ&pg=PA480 |date=4 November 2015 }}
Thomas Thomson, A System of Chemistry, 6th ed. (London, England: Baldwin, Cradock, and Joy, 1820), vol. 1, [https://books.google.com/books?id=zU40AQAAMAAJ&pg=PA272 p. 272.] {{Webarchive|url=https://web.archive.org/web/20151104174911/https://books.google.com/books?id=zU40AQAAMAAJ&pg=PA272 |date=4 November 2015 }}

Perhaps because of its strong association with elemental phosphorus, phosphine was once regarded as a gaseous form of the element, but Lavoisier (1789) recognised it as a combination of phosphorus with hydrogen and described it as phosphure d'hydrogène (phosphide of hydrogen).Note:

[https://books.google.com/books?id=d2n7gY5SI2YC&pg=PA222 On p. 222] {{Webarchive|url=https://web.archive.org/web/20170424045509/https://books.google.com/books?id=d2n7gY5SI2YC&pg=PA222 |date=24 April 2017 }} of his Traité élémentaire de chimie, vol. 1, (Paris, France: Cuchet, 1789), Lavoisier calls the compound of phosphorus and hydrogen "phosphure d'hydrogène" (hydrogen phosphide). However, [https://books.google.com/books?id=d2n7gY5SI2YC&pg=PA216 on p. 216] {{Webarchive|url=https://web.archive.org/web/20170424085705/https://books.google.com/books?id=d2n7gY5SI2YC&pg=PA216 |date=24 April 2017 }}, he calls the compound of hydrogen and phosphorus "Combinaison inconnue." (unknown combination), yet in a footnote, he says about the reactions of hydrogen with sulfur and with phosphorus: "Ces combinaisons ont lieu dans l'état de gaz & il en résulte du gaz hydrogène sulfurisé & phosphorisé." (These combinations occur in the gaseous state, and there results from them sulfurized and phosphorized hydrogen gas.)
In Robert Kerr's 1790 English translation of Lavoisier's Traité élémentaire de chimie ... — namely, Lavoisier with Robert Kerr, trans., Elements of Chemistry ... (Edinburgh, Scotland: William Creech, 1790) — Kerr translates Lavoisier's "phosphure d'hydrogène" as "phosphuret of hydrogen" ([https://archive.org/details/b28754761/page/204 p. 204]), and whereas Lavoisier — on p. 216 of his Traité élémentaire de chimie ... — gave no name to the combination of hydrogen and phosphorus, Kerr calls it "hydruret of phosphorus, or phosphuret of hydrogen" ([https://archive.org/details/b28754761/page/198 p. 198]). Lavoisier's note about this compound — "Combinaison inconnue." — is translated: "Hitherto unknown." Lavoisier's footnote is translated as: "These combinations take place in the state of gas, and form, respectively, sulphurated and phosphorated oxygen gas." The word "oxygen" in the translation is an error because the original text clearly reads "hydrogène" (hydrogen). (The error was corrected in subsequent editions.)

In 1844, Paul Thénard, son of the French chemist Louis Jacques Thénard, used a cold trap to separate diphosphine from phosphine that had been generated from calcium phosphide, thereby demonstrating that {{chem2|P2H4}} is responsible for spontaneous flammability associated with {{chem2|PH3}}, and also for the characteristic orange/brown color that can form on surfaces, which is a polymerisation product.Paul Thénard (1844) [http://gallica.bnf.fr/ark:/12148/bpt6k2977n/f652.image.langEN "Mémoire sur les combinaisons du phosphore avec l'hydrogène"] {{Webarchive|url=https://web.archive.org/web/20151015161430/http://gallica.bnf.fr/ark:/12148/bpt6k2977n/f652.image.langEN |date=15 October 2015 }} (Memoir on the compounds of phosphorus with hydrogen), Comptes rendus, 18 : 652–655. He considered diphosphine's formula to be {{chem2|PH2}}, and thus an intermediate between elemental phosphorus, the higher polymers, and phosphine. Calcium phosphide (nominally {{chem2|Ca3P2}}) produces more {{chem2|P2H4}} than other phosphides because of the preponderance of P-P bonds in the starting material.

The name "phosphine" was first used for organophosphorus compounds in 1857, being analogous to organic amines ({{chem2|NR3}}).In 1857, August Wilhelm von Hofmann announced the synthesis of organic compounds containing phosphorus, which he named "trimethylphosphine" and "triethylphosphine", in analogy with "amine" (organo-nitrogen compounds), "arsine" (organo-arsenic compounds), and "stibine" (organo-antimony compounds).{{cite journal |author1= A.W. Hofmann |author2= Auguste Cahours |year= 1857 |url= https://books.google.com/books?id=ZKkOAAAAIAAJ&q=phosphine&pg=PA523 |title= Researches on the phosphorus bases |journal= Proceedings of the Royal Society of London |number= 8 |pages= 523–527 |quote= (From page 524:) The bases Me₃P and E₃P, the products of this reaction, which we propose to call respectively trimethylphosphine and triethylphosphine, ... |access-date= 19 November 2020 |archive-date= 10 February 2022 |archive-url= https://web.archive.org/web/20220210111914/https://books.google.com/books?id=ZKkOAAAAIAAJ&q=phosphine&pg=PA523 |url-status= live }} The gas {{chem2|PH3}} was named "phosphine" by 1865 (or earlier).William Odling, A Course of Practical Chemistry Arranged for the Use of Medical Students, 2nd ed. (London, England: Longmans, Green, and Co., 1865), [https://books.google.com/books?id=PQZZAAAAYAAJ&pg=PA227 pp. 227], 230.

Structure and reactions

{{chem2|PH3}} is a trigonal pyramidal molecule with C_3v molecular symmetry. The length of the P−H bond is 1.42 Å, the H−P−H bond angles are 93.5°. The dipole moment is 0.58 D, which increases with substitution of methyl groups in the series: {{chem2|CH3PH2}}, 1.10 D; {{chem2|(CH3)2PH}}, 1.23 D; {{chem2|(CH3)3P}}, 1.19 D. In contrast, the dipole moments of amines decrease with substitution, starting with ammonia, which has a dipole moment of 1.47 D. The low dipole moment and almost orthogonal bond angles lead to the conclusion that in {{chem2|PH3}} the P−H bonds are almost entirely {{nowrap|pσ(P) – sσ(H)}} and phosphorus 3s orbital contributes little to the P-H bonding. For this reason, the lone pair on phosphorus is predominantly formed by the 3s orbital of phosphorus. The upfield chemical shift of it ³¹P NMR signal accords with the conclusion that the lone pair electrons occupy the 3s orbital (Fluck, 1973). This electronic structure leads to a lack of nucleophilicity in general and lack of basicity in particular (pK_aH = −14),{{Cite book|title=Introduction to Organic Chemistry|last1=Streitwieser|first1=Andrew|last2=Heathcock|first2=Clayton H. |last3=Kosower|first3=Edward M. |publisher=Medtech |edition=revised 4th |orig-date=1st ed. 1998|year=2017|isbn=9789385998898|location=New Delhi|pages=828}} as well as an ability to form only weak hydrogen bonds.{{ cite journal | last = Sennikov | first = P. G. | title = Weak H-Bonding by Second-Row (PH₃, H₂S) and Third-Row (AsH₃, H₂Se) Hydrides | journal = Journal of Physical Chemistry | year = 1994 | volume = 98 | issue = 19 | pages = 4973–4981 | doi = 10.1021/j100070a006 }}

The aqueous solubility of {{chem2|PH3}} is slight: 0.22 cm³ of gas dissolves in 1 cm³ of water. Phosphine dissolves more readily in non-polar solvents than in water because of the non-polar P−H bonds. It is technically amphoteric in water, but acid and base activity is poor. Proton exchange proceeds via a phosphonium ({{chem2|PH4+}}) ion in acidic solutions and via phosphanide ({{chem2|PH2−}}) at high pH, with equilibrium constants K_b = {{val|4e-28}} and K_a = {{val|41.6e-29}}. Phosphine reacts with water only at high pressure and temperature, producing phosphoric acid and hydrogen:{{Cite report |url=https://uwaterloo.ca/giga-to-nanoelectronics-centre/sites/ca.giga-to-nanoelectronics-centre/files/uploads/files/phosphine-hydrogen.pdf |title=Material Safety Data Sheet: Phosphine/hydrogen Gas Mixture |date=8 September 2008 |publisher=Matheson Tri-Gas |access-date=4 July 2022 |archive-date=5 July 2022 |archive-url=https://web.archive.org/web/20220705191148/https://uwaterloo.ca/giga-to-nanoelectronics-centre/sites/ca.giga-to-nanoelectronics-centre/files/uploads/files/phosphine-hydrogen.pdf |url-status=dead }}{{Cite journal |last1=Rabinowitz |first1=Joseph |last2=Woeller |first2=Fritz |last3=Flores |first3=Jose |last4=Krebsbach |first4=Rita |date=November 1969 |title=Electric Discharge Reactions in Mixtures of Phosphine, Methane, Ammonia and Water |url=https://www.nature.com/articles/224796a0 |journal=Nature |language=en |volume=224 |issue=5221 |pages=796–798 |doi=10.1038/224796a0 |pmid=5361652 |bibcode=1969Natur.224..796R |s2cid=4195473 |issn=1476-4687}}

{{block indent|{{chem2|PH3 + 4H2O}} {{Overset|pressure & temperature|→}} {{Chem2|H3PO4 + 4H2}}.}}

Burning phosphine in the air produces phosphoric acid:{{Cite web |date=8 July 2021 |title=Phosphine: Lung Damaging Agent |url=https://www.cdc.gov/niosh/ershdb/emergencyresponsecard_29750035.html |access-date=4 July 2022 |location=United States |publisher=National Institute for Occupational Safety and Health (NIOSH) |language=en-us}}

{{block indent|{{chem2|PH3 + 2 O2}} {{Overset|150°C|→}} {{chem2|H3PO4}}.}}

Preparation and occurrence

Phosphine may be prepared in a variety of ways.{{ cite book | last = Toy | first = A. D. F. | title = The Chemistry of Phosphorus | publisher = Pergamon Press | location = Oxford, UK | year = 1973 }} Industrially it can be made by the reaction of white phosphorus with sodium or potassium hydroxide, producing potassium or sodium hypophosphite as a by-product.

{{block indent|{{chem2|3 KOH + P4 + 3 H2O → 3 KH2PO2 + PH3}}}}

{{block indent|{{chem2|3 NaOH + P4 + 3 H2O → 3 NaH2PO2 + PH3}}}}

Alternatively, the acid-catalyzed disproportionation of white phosphorus yields phosphoric acid and phosphine. Both routes have industrial significance; the acid route is the preferred method if further reaction of the phosphine to substituted phosphines is needed. The acid route requires purification and pressurizing.

=Laboratory routes=

It is prepared in the laboratory by disproportionation of phosphorous acid:{{cite book |last1=Gokhale |first1=S. D. |last2=Jolly |first2=W. L. |title=Inorganic Syntheses |chapter=Phosphine |year=1967 |volume=9 |pages=56–58 |doi=10.1002/9780470132401.ch17|isbn=978-0-470-13168-8 }}

{{block indent|{{chem2|4 H3PO3 → PH3 + 3 H3PO4}}

Phosphine evolution occurs at around 200 °C.}}

Alternative methods are the hydrolysis zinc phosphide:

{{block indent|{{chem2|Zn3P2 + 6 H2O → 3 Zn(OH)2 + 2 PH3}}}}

{{cite journal |doi=10.15227/orgsyn.098.0289 |title=Synthesis of tert-Alkyl Phosphines: Preparation of Di-(1-adamantyl)phosphonium Trifluoromethanesulfonate and Tri-(1-adamantyl)phosphine |date=2021 |last1=Barber |first1=Thomas |first2=Liam T.|last2=Baljournal=Organic Syntheses |journal=Organic Syntheses |volume=98 |pages=289–314 }}

Some other metal phosphides could be used including aluminium phosphide, or calcium phosphide. Pure samples of phosphine, free from {{chem2|P2H4}}, may be prepared using the action of potassium hydroxide on phosphonium iodide:

{{block indent|{{chem2|[PH4]I + KOH -> PH3 + KI + H2O}}}}

=Occurrence=

Phosphine is a worldwide constituent of the Earth's atmosphere at very low and highly variable concentrations.{{ cite journal |last1=Glindemann |first1=D. |last2=Bergmann |first2=A. |last3=Stottmeister |first3=U. | last4=Gassmann |first4=G.| title = Phosphine in the lower terrestrial troposphere | journal = Naturwissenschaften | year = 1996 | volume = 83 | issue = 3 | pages = 131–133 | doi = 10.1007/BF01142179 |bibcode = 1996NW.....83..131G |s2cid=32611695 }} It may contribute significantly to the global phosphorus biochemical cycle. The most likely source is reduction of phosphate in decaying organic matter, possibly via partial reductions and disproportionations, since environmental systems do not have known reducing agents of sufficient strength to directly convert phosphate to phosphine.{{cite journal |last1=Roels |first1=J. |last2=Verstraete |first2=W. | title = Biological formation of volatile phosphorus compounds, a review paper | journal = Bioresource Technology | year = 2001 | volume = 79 | issue = 3 | pages = 243–250 | doi = 10.1016/S0960-8524(01)00032-3 | pmid = 11499578 }}

It is also found in Jupiter's atmosphere.{{cite news |last1=Kaplan |first1=Sarah |title=The first water clouds are found outside our solar system – around a failed star |url=https://www.washingtonpost.com/news/speaking-of-science/wp/2016/07/11/the-first-water-clouds-are-found-outside-our-solar-system-around-a-failed-star/ |access-date=14 September 2020 |newspaper=The Washington Post |date=11 July 2016 |archive-date=15 September 2020 |archive-url=https://web.archive.org/web/20200915162551/https://www.washingtonpost.com/news/speaking-of-science/wp/2016/07/11/the-first-water-clouds-are-found-outside-our-solar-system-around-a-failed-star/ |url-status=live }}

==Possible extraterrestrial biosignature==

In 2020 a spectroscopic analysis was reported to show signs of phosphine in the atmosphere of Venus in quantities that could not be explained by known abiotic processes.{{cite journal |title= Phosphine as a Biosignature Gas in Exoplanet Atmospheres |last1= Sousa-Silva |first1=Clara |last2=Seager |first2=Sara |last3=Ranjan |first3=Sukrit |last4=Petkowski |first4=Janusz Jurand |last5=Zhan |first5=Zhuchang |last6=Hu |first6=Renyu |last7=Bains |first7=William |publication-date= February 2020 |journal= Astrobiology |volume= 20 |number= 2 |date= 11 October 2019 |doi= 10.1089/ast.2018.1954 |bibcode= 2020AsBio..20..235S|pages= 235–268 |pmid= 31755740 |s2cid= 204401807 |arxiv= 1910.05224 }}{{cite news |url= https://news.mit.edu/2019/phosphine-aliens-stink-1218 |title= A sign that aliens could stink |date= 18 December 2019 |work= MIT News |first= Jennifer |last= Chu |access-date= 14 September 2020 |archive-date= 18 February 2021 |archive-url= https://web.archive.org/web/20210218041422/https://news.mit.edu/2019/phosphine-aliens-stink-1218 |url-status= live }}{{cite news |title= Phosphine Could Signal Existence of Alien Anaerobic Life on Rocky Planets |url= http://www.sci-news.com/astronomy/phosphine-biosignature-gas-07957.html |date= 26 December 2019 |newspaper= Sci-News |access-date= 15 September 2020 |archive-date= 14 September 2020 |archive-url= https://web.archive.org/web/20200914100028/http://www.sci-news.com/astronomy/phosphine-biosignature-gas-07957.html |url-status= live }} Later re-analysis of this work showed interpolation errors had been made, and re-analysis of data with the fixed algorithm do not result in the detection of phosphine.{{cite journal|last1=Snellen|first1=I. A. G.|title=Re-analysis of the 267-GHz ALMA observations of Venus No statistically significant detection of phosphine|journal=Astronomy and Astrophysics|volume=644|page=L2|year=2020

|arxiv=2010.09761 |bibcode=2020A&A...644L...2S|doi=10.1051/0004-6361/202039717|last2=Guzman-Ramirez|first2=L.|last3=Hogerheijde|first3=M. R.|last4=Hygate|first4=A. P. S.|last5=van der Tak|first5=F. F. S.|s2cid=224803085}}{{cite journal|arxiv=2010.15188|title=The statistical reliability of 267 GHz JCMT observations of Venus: No significant evidence for phosphine absorption|year=2021|last1=Thompson|first1=M. A.|journal=Monthly Notices of the Royal Astronomical Society: Letters|volume=501|issue=1|pages=L18–L22|doi=10.1093/mnrasl/slaa187|doi-access=free |bibcode=2021MNRAS.501L..18T|s2cid=225103303}} The authors of the original study then claimed to detect it with a much lower concentration of 1 ppb.{{cite journal|arxiv=2011.08176|title=Reply to: No evidence of phosphine in the atmosphere of Venus from independent analyses|year=2021|last1=Greaves|first1=Jane S.|last2=Richards|first2=Anita M. S.|last3=Bains|first3=William|last4=Rimmer|first4=Paul B.|last5=Clements|first5=David L.|last6=Seager|first6=Sara|last7=Petkowski|first7=Janusz J.|last8=Sousa-Silva|first8=Clara|last9=Ranjan|first9=Sukrit|last10=Fraser|first10=Helen J.|journal=Nature Astronomy|volume=5|issue=7|pages=636–639|doi=10.1038/s41550-021-01424-x|bibcode=2021NatAs...5..636G|s2cid=233296859}}{{Disputed inline|date=November 2021}}

Applications

=Organophosphorus chemistry=

Phosphine is a precursor to many organophosphorus compounds. It reacts with formaldehyde in the presence of hydrogen chloride to give tetrakis(hydroxymethyl)phosphonium chloride, which is used in textiles. The hydrophosphination of alkenes is versatile route to a variety of phosphines. For example, in the presence of basic catalysts {{chem2|PH3}} adds of Michael acceptors. Thus with acrylonitrile, it reacts to give tris(cyanoethyl)phosphine:{{cite journal|title=Phosphine in the Synthesis of Organophosphorus Compounds|first1=Boris A. |last1=Trofimov|first2=Svetlana N. |last2=Arbuzova|first3=Nina K. |last3=Gusarova|year=1999|journal=Russian Chemical Reviews|volume=68|issue=3 |pages=215–227 |doi=10.1070/RC1999v068n03ABEH000464|bibcode=1999RuCRv..68..215T |s2cid=250775640 }}

{{block indent|{{chem2|PH3 + 3 CH2\dCHZ → P(CH2CH2Z)3}} (Z is {{chem2|NO2}}, CN, or {{chem2|C(O)NH2}})}}

Acid catalysis is applicable to hydrophosphination with isobutylene and related analogues:

{{block indent|{{chem2|PH3 + R2C\dCH2 → R2(CH3)CPH2}}}}

where R is {{chem2|CH3}}, alkyl, etc.

=Microelectronics=

Phosphine is used as a dopant in the semiconductor industry, and a precursor for the deposition of compound semiconductors. Commercially significant products include gallium phosphide and indium phosphide.{{ Ullmann |last1=Bettermann |first=G. |last2=Krause |first2=W. |last3=Riess |first3=G. |last4=Hofmann |first4=T. | year = 2002 | doi = 10.1002/14356007.a19_527 | title= Phosphorus Compounds, Inorganic | isbn = 3527306730 }}

=Fumigant (pest control)=

Phosphine is an attractive fumigant because it is lethal to insects and rodents, but degrades to phosphoric acid, which is non-toxic. As sources of phosphine, for farm use, pellets of aluminium phosphide (AlP), calcium phosphide ({{chem2|Ca3P2}}), or zinc phosphide ({{chem2|Zn3P2}}) are used. These phosphides release phosphine upon contact with atmospheric water or rodents' stomach acid. These pellets also contain reagents to reduce the potential for ignition or explosion of the released phosphine.

An alternative is the use of phosphine gas itself which requires dilution with either {{chem2|CO2}} or {{chem2|N2}} or even air to bring it below the flammability point. Use of the gas avoids the issues related with the solid residues left by metal phosphide and results in faster, more efficient control of the target pests.

One problem with phosphine fumigants is the increased resistance by insects.

Toxicity and safety

Deaths have resulted from accidental exposure to fumigation materials containing aluminium phosphide or phosphine.{{cite news | url = http://www.haaretz.com/news/national/1.570036 | title = Two toddlers die after Jerusalem home sprayed for pests | newspaper = Haaretz | author1 = Ido Efrati | author2 = Nir Hasson | date = 22 January 2014 | access-date = 23 January 2014 | archive-date = 23 January 2014 | archive-url = https://web.archive.org/web/20140123064603/http://www.haaretz.com/news/national/1.570036 | url-status = live }}{{cite web |language= es |url= http://www.rtve.es/noticias/20140203/familia-alcala-guadaira-murio-tras-inhalar-fosfina-unos-tapones/869841.shtml |title= La familia de Alcalá de Guadaíra murió tras inhalar fosfina de unos tapones |date= 3 February 2014 |publisher= Radio y Televisión Española |agency= EFE |website= RTVE.es |access-date= 23 July 2014 |archive-date= 2 March 2014 |archive-url= https://web.archive.org/web/20140302205408/http://www.rtve.es/noticias/20140203/familia-alcala-guadaira-murio-tras-inhalar-fosfina-unos-tapones/869841.shtml |url-status= live }}{{cite news | url=http://www.cbc.ca/news/deaths-of-quebec-women-in-thailand-may-have-been-caused-by-pesticide-1.2569434 | title=Deaths of Quebec women in Thailand may have been caused by pesticide | date=13 March 2014 | publisher=CBC News | author=Julia Sisler | access-date=3 April 2017 | archive-date=4 April 2017 | archive-url=https://web.archive.org/web/20170404131909/http://www.cbc.ca/news/deaths-of-quebec-women-in-thailand-may-have-been-caused-by-pesticide-1.2569434 | url-status=live }}{{cite news|title=4 children killed after pesticide released toxic gas underneath their home, police say|url=https://www.washingtonpost.com/news/post-nation/wp/2017/01/03/4-children-killed-after-pesticide-released-toxic-gas-underneath-their-home-police-say/|access-date=6 January 2017|newspaper=Washington Post|author=Amy B Wang|date=3 January 2017|archive-date=25 June 2018|archive-url=https://web.archive.org/web/20180625161014/https://www.washingtonpost.com/news/post-nation/wp/2017/01/03/4-children-killed-after-pesticide-released-toxic-gas-underneath-their-home-police-say/|url-status=live}} It can be absorbed either by inhalation or transdermally. As a respiratory poison, it affects the transport of oxygen or interferes with the utilization of oxygen by various cells in the body. Exposure results in pulmonary edema (the lungs fill with fluid). Phosphine gas is heavier than air so it stays near the floor.{{cite web | url = http://www.cbc.ca/news/canada/edmonton/pesticide-blamed-in-8-month-old-s-death-in-fort-mcmurray-1.2967286 | title = Pesticide blamed in 8-month-old's death in Fort McMurray | publisher = CBC News | date = 23 February 2015 | access-date = 23 February 2015 | archive-date = 24 February 2015 | archive-url = https://web.archive.org/web/20150224051710/http://www.cbc.ca/news/canada/edmonton/pesticide-blamed-in-8-month-old-s-death-in-fort-mcmurray-1.2967286 | url-status = live }}

Phosphine appears to be mainly a redox toxin, causing cell damage by inducing oxidative stress and mitochondrial dysfunction.{{cite journal |last1=Nath |first1=NS |last2=Bhattacharya |first2=I |last3=Tuck |first3=AG |last4=Schlipalius |first4=DI |last5=Ebert |first5=PR |title=Mechanisms of phosphine toxicity |journal=Journal of Toxicology |date=2011 |volume=2011 |pages=494168 |doi=10.1155/2011/494168 |pmid=21776261|pmc=3135219 |doi-access=free }} Resistance in insects is caused by a mutation in a mitochondrial metabolic gene.

Phosphine can be absorbed into the body by inhalation. The main target organ of phosphine gas is the respiratory tract.{{cite web | url = https://www.cdc.gov/niosh/ershdb/EmergencyResponseCard_29750035.html | title = NIOSH Emergency Response Card | publisher = CDC | access-date = 6 April 2010 | archive-date = 2 October 2017 | archive-url = https://web.archive.org/web/20171002191640/https://www.cdc.gov/niosh/ershdb/emergencyresponsecard_29750035.html | url-status = live }} According to the 2009 U.S. National Institute for Occupational Safety and Health (NIOSH) pocket guide, and U.S. Occupational Safety and Health Administration (OSHA) regulation, the 8 hour average respiratory exposure should not exceed 0.3 ppm. NIOSH recommends that the short term respiratory exposure to phosphine gas should not exceed 1 ppm. The Immediately Dangerous to Life or Health level is 50 ppm. Overexposure to phosphine gas causes nausea, vomiting, abdominal pain, diarrhea, thirst, chest tightness, dyspnea (breathing difficulty), muscle pain, chills, stupor or syncope, and pulmonary edema.{{cite web | url = https://www.cdc.gov/niosh/npg/npgd0505.html | title = NIOSH pocket guide | publisher = CDC | date = 3 February 2009 | access-date = 6 April 2010 | archive-date = 11 May 2017 | archive-url = https://web.archive.org/web/20170511081428/https://www.cdc.gov/niosh/npg/npgd0505.html | url-status = live }}{{cite web | url = http://www.inchem.org/documents/pds/pds/pest46_e.htm | title = WHO – Data Sheets on Pesticides – No. 46: Phosphine | website= Inchem.org | access-date = 6 April 2010 | archive-url = https://web.archive.org/web/20100218102324/http://www.inchem.org/documents/pds/pds/pest46_e.htm | archive-date = 18 February 2010 | url-status = dead }} Phosphine has been reported to have the odor of decaying fish or garlic at concentrations below 0.3 ppm. The smell is normally restricted to laboratory areas or phosphine processing since the smell comes from the way the phosphine is extracted from the environment. However, it may occur elsewhere, such as in industrial waste landfills. Exposure to higher concentrations may cause olfactory fatigue.{{Cite report |url=https://www.cdc.gov/niosh/docs/99-126/ |title=NIOSH alert: preventing phosphine poisoning and explosions during fumigation. |date=1 September 1999 |publisher=CDC |doi=10.26616/nioshpub99126 |language=en-US |access-date=6 April 2010 |archive-date=19 June 2017 |archive-url=https://web.archive.org/web/20170619104259/https://www.cdc.gov/niosh/docs/99-126/ |url-status=live |doi-access=free }}

=Fumigation hazards=

Phosphine is used for pest control, but its usage is strictly regulated due to high toxicity.{{cite web | last=Wallstén | first=Beata | title=Åklagaren bekräftar: Familjen i Söderhamn förgiftades av fosfin | website=Dagens Nyheter | date=13 February 2024 | url=https://www.dn.se/sverige/aklagaren-bekraftar-familjen-i-soderhamn-forgiftades-av-fosfin/ | language=sv | access-date=13 February 2024| archive-url=https://archive.today/20240213090046/https://www.dn.se/sverige/aklagaren-bekraftar-familjen-i-soderhamn-forgiftades-av-fosfin/| archive-date=13 February 2024}}{{cite web | author=European Agency for Safety and Health at Work | title=Hälsorisker och förebyggande rutiner vid hantering av fumigerade containrar | url=https://osha.europa.eu/sites/default/files/845%20-%20SV.pdf | access-date=13 February 2024| archive-url=https://web.archive.org/web/20240213100055/https://osha.europa.eu/sites/default/files/845%20-%20SV.pdf| archive-date=13 February 2024}} Gas from phosphine has high mortality rate{{cite journal | last1=A Farrar | first1=Ross | last2=B Justus | first2=Angelo | last3=A Masurkar | first3=Vikram | last4=M Garrett | first4=Peter | title=Unexpected survival after deliberate phosphine gas poisoning: An Australian experience of extracorporeal membrane oxygenation rescue in this setting | journal=Anaesthesia and Intensive Care | volume=50 | issue=3 | date=2022 | issn=0310-057X | doi=10.1177/0310057X211047603 | pages=250–254| pmid=34871510 }} and has caused deaths in Sweden and other countries.{{cite news | last=| first=| title=Giftgåtan i Söderhamn: Gas tros ha dödat flickan | website=SVT Nyheter | date=13 February 2024 | url=https://www.svt.se/nyheter/lokalt/gavleborg/giftgatan-i-soderhamn-gas-tros-ha-dodat-flickan | language=sv | access-date=13 February 2024| archive-url=https://web.archive.org/web/20240213083312/https://www.svt.se/nyheter/lokalt/gavleborg/giftgatan-i-soderhamn-gas-tros-ha-dodat-flickan| archive-date=13 February 2024| last1=Berglin| first1=Rikard}}{{cite journal | last=LJ | first=Willers-Russo | title=Three fatalities involving phosphine gas, produced as a result of methamphetamine manufacturing | journal=Journal of Forensic Sciences | date=1999 | publisher=J Forensic Sci | volume=44 | issue=3 | pages=647–652 | doi=10.1520/JFS14525J | issn=0022-1198 | pmid=10408124 | url=https://pubmed.ncbi.nlm.nih.gov/10408124/ | access-date=13 February 2024 }}{{cite journal | last1=Moirangthem | first1=Sangita | last2=Vidua | first2=Raghvendra | last3=Jahan | first3=Afsar | last4=Patnaik | first4=Mrinal | last5=Chaurasia | first5=Jai | title=Phosphine Gas Poisoning | journal=American Journal of Forensic Medicine & Pathology | publisher=Ovid Technologies (Wolters Kluwer Health) | volume=44 | issue=4 | date=8 July 2023 | issn=1533-404X | doi=10.1097/paf.0000000000000855 | pages=350–353| pmid=37438888 }}

Because the previously popular fumigant methyl bromide has been phased out in some countries under the Montreal Protocol, phosphine is the only widely used, cost-effective, rapidly acting fumigant that does not leave residues on the stored product. Pests with high levels of resistance toward phosphine have become common in Asia, Australia and Brazil. High level resistance is also likely to occur in other regions, but has not been as closely monitored. Genetic variants that contribute to high level resistance to phosphine have been identified in the dihydrolipoamide dehydrogenase gene.{{cite journal |last1=Schlipalius |first1=D. I. |last2=Valmas |first2=N. |last3=Tuck |first3=A. G. |last4=Jagadeesan |first4=R. |last5=Ma |first5=L. |last6=Kaur |first6=R. |date=2012 |title=A Core Metabolic Enzyme Mediates Resistance to Phosphine Gas |journal=Science |volume=338 |issue=6108 |pages=807–810 |doi=10.1126/science.1224951 |display-authors=etal |pmid=23139334 |bibcode=2012Sci...338..807S |s2cid=10390339}} Identification of this gene now allows rapid molecular identification of resistant insects.

= Explosiveness =

Phosphine gas is denser than air and hence may collect in low-lying areas. It can form explosive mixtures with air, and may also self-ignite.

In fiction

Anne McCaffrey's Dragonriders of Pern series features genetically engineered dragons that breathe fire by producing phosphine by extracting it from minerals of their native planet.

In the 2008 pilot of the crime drama television series Breaking Bad, Walter White poisons two rival gangsters by adding red phosphorus to boiling water to produce phosphine gas. However, this reaction in reality would require white phosphorus instead, and for the water to contain sodium hydroxide.{{cite web |url=https://edu.rsc.org/analysis/breaking-bad-poisoning-gangsters-with-phosphine-gas/3007373.article |title=Breaking Bad – poisoning gangsters with phosphine gas |last=Hare |first=Jonathan |date=1 March 2011 |website=education in chemistry |publisher=Royal Society of Chemistry |archive-url=https://web.archive.org/web/20230924072242/https://edu.rsc.org/analysis/breaking-bad-poisoning-gangsters-with-phosphine-gas/3007373.article |archive-date=24 September 2023}}

Notes

References

External links

[http://www.inchem.org/documents/icsc/icsc/eics0694.htm International Chemical Safety Card 0694]
[https://www.cdc.gov/niosh/topics/phosphine/ CDC – Phosphine – NIOSH Workplace Safety and Health Topic]

Category:Fumigants

Category:Functional groups

Category:Industrial gases

Category:Phosphorus hydrides

Category:Phosphorus(−III) compounds

Category:Blood agents

Category:Pyrophoric materials