Tin(II) oxide
{{short description|Chemical compound, stannous oxide (SnO)}}
{{Redirect|SnO}}
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| verifiedrevid = 451643444
| ImageFile1 = PbO_structure.png
| ImageSize1 = 150px
| ImageFile2 = Tin(II) oxide.jpg
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| ImageFile3 = Tin(II) oxide hydrate (2).JPG
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| IUPACName = Tin(II) oxide
| OtherNames = Stannous oxide
Tin monoxide
|Section1={{Chembox Identifiers
| CASNo = 21651-19-4
| CASNo_Ref = {{cascite|correct|CAS}}
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = JB2MV9I3LS
| PubChem = 88989
| EINECS = 244-499-5
| RTECS = XQ3700000
| InChI = 1S/O.Sn
| SMILES = O=[Sn]
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|Section2={{Chembox Properties
| Formula = SnO
| Sn=1|O=1
| Appearance = black or red powder when anhydrous, white when hydrated
| Density = 6.45 g/cm3
| MeltingPtC = 1080
| MeltingPt_ref = Tin and Inorganic Tin Compounds: Concise International Chemical Assessment Document 65, (2005), World Health Organization
| BoilingPt =
| Solubility = insoluble
| MagSus = −19.0·10−6 cm3/mol
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|Section3={{Chembox Structure
| CrystalStruct = tetragonal
| SpaceGroup =
| Coordination =
| LattConst_a =
| LattConst_c =
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|Section4={{Chembox Thermochemistry
| DeltaHf = −285 kJ·mol−1{{cite book| author = Zumdahl, Steven S.|title =Chemical Principles 6th Ed.| publisher = Houghton Mifflin Company| year = 2009| isbn = 978-0-618-94690-7|page=A23}}
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|Section7={{Chembox Hazards
| ExternalSDS = [http://www.inchem.org/documents/icsc/icsc/eics0956.htm ICSC 0956]
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| FlashPt = Non-flammable
| IDLH = N.D.{{PGCH|0615}}
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|Section8={{Chembox Related
| OtherAnions = Tin sulfide
Tin selenide
Tin telluride
| OtherCations = Carbon monoxide
Silicon monoxide
Germanium(II) oxide
Lead(II) oxide
| OtherFunction = Tin dioxide
| OtherFunction_label = tin oxides
| OtherCompounds =
}}
}}
Tin(II) oxide (stannous oxide) is a compound with the formula SnO. It is composed of tin and oxygen where tin has the oxidation state of +2. There are two forms, a stable blue-black form and a metastable red form.
Preparation and reactions
File:Tin(II) oxide burning.JPG
Blue-black SnO can be produced by heating the tin(II) oxide hydrate, {{chem2|SnO*xH2O}} (x < 1) precipitated when a tin(II) salt is reacted with an alkali hydroxide such as NaOH.Egon Wiberg, Arnold Frederick Holleman (2001) Inorganic Chemistry, Elsevier {{ISBN|0-12-352651-5}}
Metastable, red SnO can be prepared by gentle heating of the precipitate produced by the action of aqueous ammonia on a tin(II) salt.
SnO may be prepared as a pure substance in the laboratory, by controlled heating of tin(II) oxalate (stannous oxalate) in the absence of air or under a CO2 atmosphere. This method is also applied to the production of ferrous oxide and manganous oxide.Satya Prakash (2000),Advanced Inorganic Chemistry: V. 1, S. Chand, {{ISBN|81-219-0263-0}}Arthur Sutcliffe (1930) Practical Chemistry for Advanced Students (1949 Ed.), John Murray - London.
:SnC2O4·2H2O → SnO + CO2 + CO + 2 H2O
Tin(II) oxide burns in air with a dim green flame to form SnO2.
:2 SnO + O2 → 2 SnO2
When heated in an inert atmosphere initially disproportionation occurs giving Sn metal and Sn3O4 which further reacts to give SnO2 and Sn metal.
:4SnO → Sn3O4 + Sn
:Sn3O4 → 2SnO2 + Sn
SnO is amphoteric, dissolving in strong acid to give tin(II) salts and in strong base to give stannites containing Sn(OH)3−. It can be dissolved in strong acid solutions to give the ionic complexes Sn(OH2)32+ and Sn(OH)(OH2)2+, and in less acid solutions to give Sn3(OH)42+. Note that anhydrous stannites, e.g. K2Sn2O3, K2SnO2 are also known.{{cite journal | doi = 10.1002/anie.197804491 | title = The First Oxostannate(II): K2Sn2O3 | journal = Angewandte Chemie International Edition in English | volume = 17 | issue = 6 | pages = 449–450 | year = 1978 | last1 = Braun | first1 = Rolf Michael | last2 = Hoppe | first2 = Rudolf }}{{cite journal | doi = 10.1002/zaac.19824850103| title = Über Oxostannate(II). III. K2Sn2O3, Rb2Sn2O3 und Cs2Sn2O3 - ein Vergleich| journal = Zeitschrift für Anorganische und Allgemeine Chemie| volume = 485| pages = 15–22| year = 1982| last1 = Braun| first1 = R. M.| last2 = Hoppe| first2 = R.}}R M Braun R Hoppe Z. Naturforsch. (1982), 37B, 688-694
SnO is a reducing agent and is thought to reduce copper(I) to metallic clusters in the manufacture of so-called "copper ruby glass".{{citation| title = Colour development in copper ruby alkali silicate glasses. Part I: The impact of tin oxide, time and temperature | last1 = Bring | first1 = T. | last2 = Jonson| first2 = B.| last3 = Kloo| first3 = L. | last4 = Rosdahl| first4 = J | last5 = Wallenberg| first5 = R.|journal = Glass Technology, Eur. J. Glass Science & Technology, Part A| volume = 48 |number = 2 |pages = 101–108 | year = 2007 | issn = 1753-3546 }}
Structure
Black, α-SnO adopts the tetragonal PbO layer structure containing four coordinate square pyramidal tin atoms.Wells A.F. (1984) Structural Inorganic Chemistry 5th edition Oxford Science Publications {{ISBN|0-19-855370-6}} This form is found in nature as the rare mineral romarchite.{{cite journal | doi = 10.2113/gscanmin.41.3.649| title = On Type Romarchite and Hydroromarchite from Boundary Falls, Ontario, and Notes on Other Occurrences| journal = The Canadian Mineralogist| volume = 41| issue = 3| pages = 649–657| year = 2003| last1 = Ramik| first1 = R. A.| last2 = Organ| first2 = R. M.| last3 = Mandarino| first3 = J. A.| bibcode = 2003CaMin..41..649R}} The asymmetry is usually simply ascribed to a sterically active lone pair; however, electron density calculations show that the asymmetry is caused by an antibonding interaction of the Sn(5s) and the O(2p) orbitals.{{cite journal | doi = 10.1103/PhysRevB.70.235114| title = Electronic structures of rocksalt, litharge, and herzenbergite SnO by density functional theory| journal = Physical Review B| volume = 70| issue = 23| pages = 235114| year = 2004| last1 = Walsh| first1 = Aron| last2 = Watson| first2 = Graeme W.| bibcode = 2004PhRvB..70w5114W}} The electronic structure and chemistry of the lone pair determines most of the properties of the material.{{Cite journal|last1=Mei|first1=Antonio B.|last2=Miao|first2=Ludi|last3=Wahila|first3=Matthew J.|last4=Khalsa|first4=Guru|last5=Wang|first5=Zhe|last6=Barone|first6=Matthew|last7=Schreiber|first7=Nathaniel J.|last8=Noskin|first8=Lindsey E.|last9=Paik|first9=Hanjong|last10=Tiwald|first10=Thomas E.|last11=Zheng|first11=Qiye|date=2019-10-21|title=Adsorption-controlled growth and properties of epitaxial SnO films|url=https://link.aps.org/doi/10.1103/PhysRevMaterials.3.105202|journal=Physical Review Materials|volume=3|issue=10|pages=105202|doi=10.1103/PhysRevMaterials.3.105202|bibcode=2019PhRvM...3j5202M|s2cid=208008118}}
Non-stoichiometry has been observed in SnO.{{cite journal | doi = 10.1103/PhysRevB.56.5186| title = Cation nonstoichiometry in tin-monoxide-phaseSn1−δOwith tweed microstructure| journal = Physical Review B| volume = 56| issue = 9| pages = 5186–5192| year = 1997| last1 = Moreno| first1 = M. S.| last2 = Varela| first2 = A.| last3 = Otero-Díaz| first3 = L. C.}}
The electronic band gap has been measured between 2.5eV and 3eV.Science and Technology of Chemiresistor Gas Sensors By Dinesh K. Aswal, Shiv K. Gupta (2006), Nova Publishers, {{ISBN|1-60021-514-9}}
Uses
The dominant use of stannous oxide is as a precursor in manufacturing of other, typically divalent, tin compounds or salts. Stannous oxide may also be employed as a reducing agent and in the creation of ruby glass.[http://kth.diva-portal.org/smash/get/diva2:11081/FULLTEXT01 "Red Glass Coloration - A Colorimetric and Structural Study" By Torun Bring. Pub. Vaxjo University.] It has a minor use as an esterification catalyst.
Cerium(III) oxide in ceramic form, together with Tin(II) oxide (SnO) is used for illumination with UV light.{{cite journal |url=http://jdr.iadrjournals.org/cgi/reprint/59/9/1501.pdf |title=Spectral Studies of New Luminophors for Dental Porcelain |journal=Journal of Dental Research |volume=59 |issue=9 |pages=1501–1506 |doi=10.1177/00220345800590090801 |pmid=6931128 |publisher=Jdr.iadrjournals.org |access-date=2012-04-05 |year=1980 |last1=Peplinski |first1=D.R. |last2=Wozniak |first2=W.T. |last3=Moser |first3=J.B. |s2cid=20191368 }}{{Dead link|date=July 2018 |bot=InternetArchiveBot |fix-attempted=no }}
References
{{reflist}}
{{Tin compounds}}
{{Oxides}}