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Revision as of 07:17, 28 August 2011 edit75.18.198.137 (talk)No edit summary← Previous edit		Latest revision as of 08:25, 31 August 2022 edit undoA1113595596 (talk | contribs)240 edits Add InChI, InChIKey, and SMILES
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	{{chembox		{{chembox
			| Verifiedfields = changed
⚫	| verifiedrevid = 413854533
			| Watchedfields = changed
⚫	| Name = Silver(I) selenide
		⚫	| verifiedrevid = 447104195
⚫	| ImageFile = Ag2Sestructure.png
		⚫	| Name = Silver(I) selenide
	<!-- | ImageSize = 200px -->
		⚫	| ImageFile = Ag2Sestructure.png
	| ImageName = Silver(I) selenide		| ImageName = Silver(I) selenide
	| OtherNames = ]		| OtherNames = ] <br/> Argentous selenide
⚫	| Section1 = {{Chembox Identifiers
			| IUPACName = Silver(I) selenide
			| SystematicName =
		⚫	| Section1 = {{Chembox Identifiers
			| CASNo_Ref = {{cascite|correct|CAS}}
	| CASNo = 1302-09-6		| CASNo = 1302-09-6
			| UNII_Ref = {{fdacite|correct|FDA}}
			| UNII = QZ0B90W7EQ
			| PubChem = 6914520
			| InChI = 1S/2Ag.Se
			| InChIKey = GNWCVDGUVZRYLC-UHFFFAOYSA-N
			| SMILES = ..
	}}		}}
	| Section2 = {{Chembox Properties		| Section2 = {{Chembox Properties
	| Formula = Ag<sub>2</sub>Se		| Formula = Ag<sub>2</sub>Se
	| MolarMass = 294.7 g/mol		| MolarMass = 294.7 g/mol
	| Density = 8.216 g/cm<sup>3</sup>, solid		| Density = 8.216 g/cm<sup>3</sup>, solid
	| MeltingPt = 880 °C		| MeltingPtC = 896.85
	| BoilingPt =		| BoilingPt =
	| BandGap = 0.15 eV <ref name=r1>{{cite book|url=http://books.google.com/books?id=v_8sMfNAcA4C&pg=PA461|page=461|title=Semiconductors: data handbook|author=O. Madelung|publisher=Birkhäuser|year=2004|isbn=3540404880}}</ref>		| BandGap = 0.15 eV <ref name=r1>{{cite book|url=https://books.google.com/books?id=v_8sMfNAcA4C&pg=PA461|page=461|title=Semiconductors: data handbook|author=O. Madelung|publisher=Birkhäuser|year=2004|isbn=978-3-540-40488-0}}</ref>
			| Solubility = insoluble
	}}		}}
	| Section3 = {{Chembox Structure		| Section3 = {{Chembox Structure
	| CrystalStruct = ], ]		| CrystalStruct = ], ]
	| SpaceGroup = P2<sub>1</sub>2<sub>1</sub>2<sub>1</sub>, No. 19		| SpaceGroup = P2<sub>1</sub>2<sub>1</sub>2<sub>1</sub>, No. 19
	}}		}}
	| Section6 = {{Chembox Hazards		| Section4 = {{Chembox Thermochemistry
			| DeltaHfus = 56.9 J/g
			}}
			| Section5 =
			| Section6 = {{Chembox Hazards
	| MainHazards =		| MainHazards =
	| FlashPt =		| FlashPt =
	| Autoignition =		| AutoignitionPt =
	}}		}}
	| Section7 = {{Chembox Thermochemistry		| Section7 = {{Chembox Thermochemistry
	| DeltaHf =		| DeltaHf =
	| DeltaHc =		| DeltaHc =
	| Entropy =		| Entropy =
	| HeatCapacity =}}		| HeatCapacity =
			}}
	}}		}}
		⚫	'''Silver selenide''' (Ag<sub>2</sub>Se) is the reaction product formed when selenium toning analog silver gelatine photo papers in ]. The selenium toner contains ] (Na<sub>2</sub>SeO<sub>3</sub>) as one of its active ingredients, which is the source of the selenide (Se<sup>2−</sup>) anion combining with the ] in the toning process.
		⚫	It is found in nature as the mineral '''naumannite''', a comparatively rare silver mineral which has nevertheless become recognized as important silver compound in some low-sulfur silver ores from mines in Nevada and Idaho.<ref>http://nevada-outback-gems.com/Reference_pages/sulfide_ores.htm Notes on naumannite.</ref><ref>{{Cite book|title=The Geology of Ore Deposits|last1=Guilbert|first1=John M.|last2=Park Jr|first2=Charles F.|date=2007-02-09|publisher=Waveland Press|isbn=978-1-4786-0887-5|pages=557}}</ref>
	<!--| ] 56.9 J/g nowhere to put this in the new chembox structure-->
		⚫	==Structure==
⚫	'''Silver selenide''' (Ag<sub>2</sub>Se) is a clear, ] compound. It is the reaction product formed when selenium toning analog silver gelatine photo papers in ]. The selenium toner contains ] (Na<sub>2</sub>SeO<sub>3</sub>) as one of its active ingredients, which is the source of the selenide (Se<sup>2-</sup>) anion combining with the ] in the toning process.
		⚫	Silver selenide has two crystal phases on the bulk phase diagram. At lower temperatures, it has an ] structure, β-Ag<sub>2</sub>Se. This orthorhombic phase, stable at room temperature, is a ], with space group P2<sub>1</sub>2<sub>1</sub>2<sub>1</sub>. The exact size of the band gap has been given variously from 0.02 eV to 0.22 eV.<ref>{{cite journal|journal=Physical Review B|volume=54|issue=1|pages=190–202|year=1996|author1=Kirchhoff F. |author2=Holender J.M. |author3=Gillan M.J. |doi=10.1103/PhysRevB.54.190|title=Structure, dynamics, and electronic structure of liquid Ag-Se alloys investigated by ab initio simulation|pmid=9984246|arxiv=mtrl-th/9602001|bibcode=1996PhRvB..54..190K|s2cid=9316728}}</ref>
			There is also a high temperature cubic phase, α-Ag<sub>2</sub>Se.,<ref name="AnJi2009">{{cite journal|last1=An|first1=Boo Hyun|last2=Ji|first2=Hye Min|last3=Wu|first3=Jun-Hua|last4=Cho|first4=Moon Kyu|last5=Yang|first5=Ki-Yeon|last6=Lee|first6=Heon|last7=Kim|first7=Young Keun|title=Phase changeable silver selenide thin films fabricated by pulse electrodeposition|journal=Current Applied Physics|volume=9|issue=6|year=2009|pages=1338–1340|issn=1567-1739|doi=10.1016/j.cap.2008.12.017|bibcode=2009CAP.....9.1338A}}</ref> which it transforms into at temperatures above 130&nbsp;°C. This high temperature phase has ] Im{{Overline|3}}m, No. 229, ] cI20. The phase transition increases ionic conductivity by 10,000 times to about 2 S/cm.
⚫	It is found in nature as the mineral naumannite, a comparatively rare silver mineral which has nevertheless become recognized as important silver compound in some low-sulfer silver ores from mines in Nevada.<ref>http://nevada-outback-gems.com/Reference_pages/sulfide_ores.htm Notes on naumannite.</ref>
			A third ] phase with a ] structure and space group P2<sub>1</sub>/n is known to form for colloidal Ag{{sub|2}}Se nanocrystals.<ref name="ag2se">{{Cite journal|url=https://pubs.acs.org/doi/10.1021/acs.nanolett.1c02045|doi = 10.1021/acs.nanolett.1c02045|title = Crystal Structure of Colloidally Prepared Metastable Ag2Se Nanocrystals|year = 2021|last1 = Tappan|first1 = Bryce A.|last2 = Zhu|first2 = Bonan|last3 = Cottingham|first3 = Patrick|last4 = Mecklenburg|first4 = Matthew|last5 = Scanlon|first5 = David O.|last6 = Brutchey|first6 = Richard L.|journal = Nano Letters|volume = 21|issue = 13|pages = 5881–5887|pmid = 34196567|bibcode = 2021NanoL..21.5881T|s2cid = 235698416}}</ref> The crystal structure of this polymorph is highly related to the ] phase of ]. For Ag{{sub|2}}Se, this polymorph is increasingly unstable for larger crystallites, which explains its absence on the bulk phase diagram.<ref>{{Cite journal|url=https://pubs.acs.org/doi/10.1021/nl4041498|doi=10.1021/nl4041498|title=Solid-Phase Flexibility in Ag2Se Semiconductor Nanocrystals|year=2014|last1=Sahu|first1=Ayaskanta|last2=Braga|first2=Daniele|last3=Waser|first3=Oliver|last4=Kang|first4=Moon Sung|last5=Deng|first5=Donna|last6=Norris|first6=David J.|journal=Nano Letters|volume=14|issue=1|pages=115–121|pmid=24295334|bibcode=2014NanoL..14..115S}}</ref> It is thought that the influence of the ] plays a role stabilizing this phase on the nanoscale, thus allowing its experimental isolation. Electronic structure calculations for this polymorph of Ag{{sub|2}}Se suggest that it is a narrow-gap semiconductor,<ref name="ag2se" /> which is supported by experimental evidence as well.<ref>{{Cite journal|url=https://pubs.rsc.org/en/content/articlelanding/2012/cc/c2cc30539a|doi = 10.1039/C2CC30539A|title = Quantum confinement in silver selenide semiconductor nanocrystals|year = 2012|last1 = Sahu|first1 = Ayaskanta|last2 = Khare|first2 = Ankur|last3 = Deng|first3 = Donna D.|last4 = Norris|first4 = David J.|journal = Chemical Communications|volume = 48|issue = 44|pages = 5458–5460|pmid = 22540121}}</ref> Prior to 2021, the crystal structure of this polymorph was unknown, and this material was informally referred to as a "]" or "pseudo-tetragonal" polymorph of Ag{{sub|2}}Se.<ref>{{Cite journal|url=https://pubs.acs.org/doi/10.1021/cm502317g|doi=10.1021/cm502317g|title=Tetragonal–Orthorhombic–Cubic Phase Transitions in Ag2Se Nanocrystals|year=2014|last1=Wang|first1=Junli|last2=Fan|first2=Weiling|last3=Yang|first3=Juan|last4=Da|first4=Zulin|last5=Yang|first5=Xiaofei|last6=Chen|first6=Kangmin|last7=Yu|first7=Huan|last8=Cheng|first8=Xiaonong|journal=Chemistry of Materials|volume=26|issue=19|pages=5647–5653}}</ref> This terminology, while not technically correct, is prevalent in the literature pertaining to this metastable phase of Ag{{sub|2}}Se.
⚫	==Structure==
⚫	Silver selenide normally exists in the ] β phase but at temperatures above 130 °C transforms into the cubic α-Ag<sub>2</sub>Se (] Im-3m, No. 229, ] cI20). The phase transition increases ionic conductivity by 10,000 times to about 2 S/cm <ref>{{cite journal|journal=Physical Review B|volume=54|pages=190–202|year=1996|author=Kirchhoff F., Holender J.M., Gillan M.J.|doi=10.1103/PhysRevB.54.190|title=Structure, dynamics, and electronic structure of liquid Ag-Se alloys investigated by ab initio simulation}}</ref>
	==References==		==References==
	{{reflist}}		{{reflist}}
	{{Silver compounds}}		{{Silver compounds}}
			{{Selenides}}
	]		]
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	{{inorganic-compound-stub}}		{{inorganic-compound-stub}}
	]
	]
	]