查看“︁氫硫基自由基”︁的源代码

{{For|包含巰基官能團的有機硫化合物|硫醇}}
{{Chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 470473350
| ImageFile = HS-CM-3D-balls.png
| ImageFile_Ref = {{chemboximage|correct|??}}
| ImageSize = 100
| ImageName = 氫硫基自由基的球棒模型
| SystematicName = Sulfanyl<ref name = "sulfanyl (CHEBI:29312)">{{cite web|title = sulfanyl (CHEBI:29312)|url = http://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:29312|work = Chemical entities of biological interest|publisher = European Bioinformatics Institute|accessdate = 8 October 2011|location = UK|date = 6 November 2006|at = Main|archive-date = 2017-12-27|archive-url = https://web.archive.org/web/20171227180358/http://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:29312|dead-url = no}}</ref> ''（取代法）''<br />
Hydridosulfur(•)<ref name = "sulfanyl (CHEBI:29312)" />''（加合法）''
| OtherNames = λ<sup>1</sup>-Sulfane<ref>{{cite web|title = Mercapto radical – Compound summary|url = https://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?cid=5460613&loc=ec_rcs|work = PubChem Compound|publisher = National Center for Biotechnology Information|accessdate = 12 October 2011|location = USA|date = 16 September 2004|at = Identification and related records}}</ref><br />一氫化硫
|Section1={{Chembox Identifiers
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 13940-21-1
| PubChem = 5460613
| ChemSpiderID = 4574111
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChEBI = 29312
| ChEBI_Ref = {{ebicite|correct|EBI}}
| Gmelin = 299
| SMILES = [SH]
| InChI = 1S/HS/h1H
| InChI_Ref = {{stdinchicite|correct|chemspider}}
| InChIKey = PXQLVRUNWNTZOS-UHFFFAOYSA-N
| InChIKey_Ref = {{stdinchicite|correct|chemspider}}
}}
|Section2={{Chembox Properties
| Formula = {{Chem|HS}}<sup>•</sup>
| MolarMass = 33.073 g mol<sup>−1</sup>
| Appearance = 黃色氣體<ref name="Zahnle">{{Cite journal|title=Atmospheric sulfur photochemistry on hot Jupiters|journal = The Astrophysical Journal|volume = 701|issue = 1|pages = L20–L24|last=Zahnle|first=Kevin |author2=Mark S. Marley |author3=R. S. Freedman |author4=K. Lodders |author5=J. J. Fortney |date=26 June 2009|arxiv = 0903.1663v2|doi = 10.1088/0004-637X/701/1/L20|bibcode = 2009ApJ...701L..20Z}}</ref>
| Solubility = 產生反應
}}
|Section3={{Chembox Thermochemistry
| DeltaHf = 139.33 kJ mol<sup>−1</sup>
| Entropy = 195.63 J K<sup>−1</sup> mol<sup>−1</sup>
}}
|Section4={{Chembox Related
| Function = 自由基
| OtherFunctn  = [[羥基自由基]]
| OtherCpds  = [[硫化氫]]<br />
[[二硫化氫]]
}}
}}

'''氫硫基自由基'''是一種[[自由基]]，具有一顆氫原子和一顆硫原子。

== 產生 ==
於1939年[[加利福尼亞大學]]瑪格麗特·N·劉易斯及約翰·U·懷特首次發現其存在。<ref name="Lewis">{{cite journal|last=Lewis|first=Margaret|author2=John U. White |year=1939|title=The band spectrum of HS|journal=Physical Review|volume=55|issue=10|pages=894–898|doi=10.1103/PhysRev.55.894|bibcode = 1939PhRv...55..894L }}</ref>他們對[[硫化氫]]進行射頻放電以取得氫硫基自由基，<ref>{{cite journal|last=Harrison|first=Jeremy J.|author2=Bryce E. Williamson|date=November 2005|title=Magnetic circular dichroism of the mercapto radical in noble-gas matrices|journal=Journal of the Indian Institute of Science|volume=85|pages=391–402|url=http://journal.library.iisc.ernet.in/vol200506/paper6/391-402.pdf|author=|access-date=2019-11-30|archive-url=https://web.archive.org/web/20120415053454/http://journal.library.iisc.ernet.in/vol200506/paper6/391-402.pdf|archive-date=2012-04-15|dead-url=yes}}</ref>從中觀察到對應其<big><sup>2</sup>Σ<sup>+</sup> ← <sup>2</sup>Π<sub>i</sub></big>躍遷的325 nm[[吸收線]]。

它亦可於硫化氫以紫外線產生，吸收峰值為190 nm波長的輻射。<ref>{{cite book|last1=Hollaender|first1=Alexander|last2=Livingston|first2=Robert|title=Radiation Biology|chapter-url=https://archive.org/stream/radiationbiology02holl/radiationbiology02holl_djvu.txt|year=1955|publisher=McGraw Hill|page=27|chapter=1}}</ref>

[[硫醇]]（如乙硫醇）的熱分解會產生氫硫基自由基。<ref>{{cite journal|last=Sehon|first=A. H.|author2=B. deB. Darwent |date=October 1954|title=The thermal decomposition of mercaptans|journal=Journal of the American Chemical Society|volume=76|issue=19|pages=4806|doi=10.1021/ja01648a011}}</ref>其亦可由[[硫酸鈰(IV)]]氧化硫化氫離子（HS<sup>−</sup>）產生。<ref name=pos>{{cite journal|last=Pos|first=Willer H.|author2=Daniel D. Riemer |author3=Rod G. Zika |year=1998|title=Carbonyl sulfide (OCS) and carbon monoxide (CO) in natural waters: evidence of a coupled production pathway|journal=Marine Chemistry|volume=62|issue=1–2|pages=89–101|doi=10.1016/S0304-4203(98)00025-5}}</ref>

其在生物的代謝作用中對硫化氫的反應，如進行[[解毒]]時也會出現。人體中的{{link-en|SOD1酶|SOD1}}可將HS<sup>−</sup>轉為{{Chem|HS}}<sup>•</sup>。<ref name="lyons">{{cite book|url=http://www.ffame.org/tlyons/mibs36.125-177.pdf|title=Biological chemistry of copper-zinc superoxide dismutase and its link to amyotrophic lateral sclerosis|last=Lyons|first=Thomas J.|author2=Edith Butler Gralla|author3=Joan Selverstone Valentine|year=1999|work=Metal ions in biological systems|publisher=Marcel Decker Inc|page=139|accessdate=10 October 2011|location=Basel, Switzerland|isbn=978-0-8247-1956-2}}{{Dead link|date=2019年12月 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>硫酸鹽還原細菌中的{{link-en|黃色素c硫化物脫氫酶|Flavocytochrome c sulfide dehydrogenase}}亦能催化硫化氫離子的氧化作用，移除電子並產生該自由基。<ref>{{cite journal|last=Sorokina|first=Dimitry Yu|author2=Govardus A.H de Jong |author3=Lesley A. Robertson |author4=Gijs J. Kuenen |date=1 May 1998|title=Purification and characterization of sulfide dehydrogenase from alkaliphilic chemolithoautotrophic sulfur-oxidizing bacteria|url=https://archive.org/details/sim_febs-letters_1998-05-01_427_1/page/11|journal=FEBS Letters|volume=427|issue=1|pages=11–14|pmid=9613590|doi=10.1016/S0014-5793(98)00379-2}}</ref>

當含硫礦物被三價鐵離子溶濾時會產生氫硫基自由基離子：
:<math>\mathsf{MS + Fe^{3+} + 2H^+ \ \xrightarrow{}\ M^{2+} + Fe^{2+} + H_2S^{\bullet+}}</math>
該離子其後便讓水吸收氫離子而成為氫硫基自由基。上述的M為一種金屬，例如銅或鋅。<ref name="schippers">{{cite journal|last=Schippers|first=Axel|author2=Wolfgang Sand |date=January 1999 |title=Bacterial leaching of metal sulfides proceeds by two indirect mechanisms via thiosulfate or via polysulfides and sulfur|journal=Applied and Environmental Microbiology|volume=65|issue=1|pages=319–321|url=http://aem.asm.org/cgi/reprint/65/1/319.pdf|pmid=9872800|pmc=91023}}</ref>此反應亦有發展以[[生物濾化]]提煉金屬礦物的潛在可能。

== 自然界的存在 ==
氫硫基自由基由山村一誠等首次於星際空間發現，他們在2000年發表其於[[仙女座R]]觀測到相關吸收線的文章。<ref>{{cite journal|last=Yamamura|first=Issei|author2=Kawaguchi, K.|author3=Ridgway, S. T.|date=2000-1|title=Identification of SH ∆v=1 Ro-vibrational Lines in R Andromedae|journal=The Astrophysical Journal|volume=258|issue=1|pages=L33-L36 |doi=10.1086/312420}}</ref>它被觀測到的紫外譜線分別為：326.0459、327.5468、328.9749、330.0892及330.1112 nm。<ref>{{cite journal|volume=387|doi=10.1051/0004-6361:20020364|bibcode=2002A&A...387L...6B|date=May 2002|journal=Astronomy and Astrophysics|title=Detection of the mercapto radical SH in the solar atmosphere|author1=Sveta V. Berdyugina  |author2=W.C. Livingston |lastauthoramp=yes |pages=L6–L9 }}</ref>

它預計是在[[氣態巨行星]]（如[[木星]]）及[[棕矮星]]存在的三大含硫氣體之一，<ref name=Visscher>{{cite journal|last=Visscher|first=Channon|author2=Katharina Lodders , and Bruce Fegley, Jr.|date=10 September 2006|title=Atmospheric chemistry in giant planets, brown dwarfs, and low-mass dwarf stars. II. Sulfur and phosphorus|journal=The Astrophysical Journal|volume=648|pages=1181–1195|url=http://iopscience.iop.org/0004-637X/648/2/1181/63994.text.html|issue=2|arxiv=astro-ph/0511136|doi=10.1086/506245|bibcode = 2006ApJ...648.1181V |last3=Fegley|first3=Bruce}}</ref>亦很可能於已冷卻恆星中存在。它已在星際氣體中探測到，<ref>{{cite web|url=https://www.npr.org/2011/10/01/140877924/flying-telescope-makes-an-out-of-this-world-find|title=Flying telescope makes an out-of-this-world find|last=Palca|first=Joe|date=1 October 2011|publisher=NPR|accessdate=8 October 2011|archive-date=2020-08-08|archive-url=https://web.archive.org/web/20200808070000/https://www.npr.org/2011/10/01/140877924/flying-telescope-makes-an-out-of-this-world-find|dead-url=no}}</ref>亦可能存在於[[彗星]]中。<ref>{{cite web|title= The cosmic ice laboratory – Cometary molecules|url= http://science.gsfc.nasa.gov/691/cosmicice/cometary.html|accessdate= 2019-11-30|archive-date= 2016-12-31|archive-url= https://web.archive.org/web/20161231230030/http://science.gsfc.nasa.gov/691/cosmicice/cometary.html|dead-url= no}}</ref>

在地球的大氣層中亦有該自由基，由自然發生的（例如[[光分解作用]]<ref name="Furones">{{cite web|url=https://estudogeral.sib.uc.pt/jspui/bitstream/10316/7489/3/thesis-MYBF.pdf|title=A theoretical study on the HSO<sub>2</sub> molecular system|last=Furones|first=Maikel Yusat Ballester|year=2008|publisher=Universidade de Coimbra|pages=1, 37|accessdate=20 October 2011|location=Coimbra|archive-url=https://web.archive.org/web/20120419012059/https://estudogeral.sib.uc.pt/jspui/bitstream/10316/7489/3/thesis-MYBF.pdf|archive-date=2012-04-19|dead-url=yes}}</ref>）及由人為除臭引致的硫化氫降解形成。<ref>{{cite web |url=http://www.ispc-conference.org/ispcproc/papers/275.pdf |title=Environmental odour control by atmospheric dielectric barrier discharge |last=Mercado-Cabrera |first=Antonio |author2=B. Jaramillo-Sierra |author3=S.R. Barocio |author4=R. Valencia-Alvarado |author5=M. Pacheco-Pacheco |author6=R. Peña-Eguiluz |author7=R. Lopez-Callejas |author8=A. Muñoz-Castro |author9=A. De la Piedad-Beneitez |date=29 April 2009 |publisher=ISPC |accessdate=20 October 2011 |archive-date=2013-09-27 |archive-url=https://web.archive.org/web/20130927215053/http://www.ispc-conference.org/ispcproc/papers/275.pdf |dead-url=no }}</ref>另外，當地球大氣層中的[[羥基自由基]]與硫化氫、[[二硫化碳]]或[[羰基硫]]反應亦會產生氫硫基自由基、[[二氧化碳]]和水。這自由基在大氣層中有多種反應，如與[[二氧化氮|NO<sub>2</sub>]]產生HSNO<sub>2</sub>及HSONO，後者分解為HSO及[[一氧化氮|NO]]；亦會與氧氣及[[一氧化二氮]]反應。<ref name="resende">{{cite journal|last=Resende|first=Stella M.|year=2007|title=The atmospheric oxidation of the HS radical: Reaction with NO<sub>2</sub>|url=https://archive.org/details/sim_journal-of-atmospheric-chemistry_2007-01_56_1/page/21|journal=Journal of Atmospheric Chemistry|volume=56|issue=1|pages=21–32|doi=10.1007/s10874-006-9040-z|bibcode=2006JAtC...56...21R}}</ref>其與氯氣反應會產生HSCl及Cl<sup>•</sup>自由基；<ref>{{cite journal|last=Resende|first=Stella M.|author2=Fernando R Ornellas |date=25 February 2000|title=Atmospheric reaction between the HS radical and chlorine|journal=Chemical Physics Letters|volume=318|issue=4–5|pages=340–344|doi=10.1016/S0009-2614(00)00019-1|bibcode=2000CPL...318..340R}}</ref>與臭氧反應則產生HSO<sup>•</sup>及氧。<ref name="yosh">{{cite journal|last=Yoshimura|first=Yasunori|author2=Toshio Kasai, Hiroshi Ohoyama and Keiji Kuwata|year=1995|title=Nascent HF + and HSO(2A') formations in the elementary reactions of F + H<sub>2</sub>S and HS + O<sub>3</sub> and the internal energy distributions|url=https://archive.org/details/sim_canadian-journal-of-chemistry_1995-02_73_2/page/204|journal=Canadian Journal of Chemistry|volume=73|issue=2|pages=204–221|doi=10.1139/v95-029|last3=Ohoyama|first3=Hiroshi|last4=Kuwata|first4=Keiji}}</ref>

理論上在含有硫化氫的行星大氧層在足夠溫度及壓力下便能分解成自由基。在特定溫度及壓力下兩者比例為：
:<math>\mathsf{\log(X_{H_2S}/X_{HS}) = -3.37 + 8785/T + 0.5 \log P_T + 0.5 \log X_{H_2}}</math>

在一個以氫氣為主的氣態巨行星或恆星，在以下情況氫硫基自由基與硫化氫為同一水平：
:<math>\mathsf{\log P_T = 6.82 - 17570/T}</math>

而在更高溫度中自由基會分解成氣態硫及氫氣，在以下情況它與氣態硫為同一水平：
:<math alt>\mathsf{\log P_T = 4.80 - 14522/T}</math>.

這兩條方程會於1509 K及1.51 Pa處相交，在更低的度及壓力下該自由基被排除在外。<ref name=Visscher/>

== 特性 ==

氫硫基自由基中氫與硫的原子間距為0.134 nm。<ref name="Ellingson">{{cite journal|url=http://static.msi.umn.edu/rreports/2007/267.pdf|title=Explanation of the unusual temperature dependence of the atmospheric important <sup>•</sup>OH + H<sub>2</sub>S → H<sub>2</sub>O + <sup>•</sup>SH reaction and prediction of the rate constant at combustion temperatures|last=Ellingson|first=Benjamin A.|author2=Donald G. Truhlar|date=1 August 2007|accessdate=20 October 2011|doi=10.1021/ja072538b|pmid=17910447|journal=J. Am. Chem. Soc.|volume=129|issue=42|pages=12765–12771 [12769]|format=reprint|author=|archive-url=https://web.archive.org/web/20120425081731/http://static.msi.umn.edu/rreports/2007/267.pdf|archive-date=2012-04-25|dead-url=yes}}</ref>其[[電離能]]為10.4219 eV；<ref>{{cite journal|last=Cheng|first=B. M.|author2=E. P. Chew, W. C. Hung, J. Eberhard and Y. P. Lee|date=May 1998|title=Photoionization studies of sulfur radicals and products of their reactions|journal=Journal of Synchrotron Radiation|volume=5|issue=3|pages=1041–3|doi=10.1107/S0909049597016075|pmid=15263738|last3=Hung|first3=Wen-Ching|last4=Eberhard|first4=Jürg|authorlink5=Yuan-Pern Lee|last5=Lee|first5=Yuan-Pern|url=http://journals.iucr.org/s/issues/1998/03/00/mz3378/mz3378.pdf}}</ref>成為HS<sup>−</sup>的還原電位為0.92 eV。<ref name="das">{{cite journal|last=Das|first=T. N.|author2=R. E. Huie |author3=P. Neta |author4=S. Padmaja |date=11 June 1999|title=Reduction potential of the sulfhydryl radical: pulse radiolysis and laser flash photolysis studies of the formation and reactions of <sup>•</sup>SH and HS–SH<sup>•−</sup> in aqueous solutions|journal=The Journal of Physical Chemistry A|volume=103|issue=27|pages=5221–5226|doi=10.1021/jp9907544|bibcode=1999JPCA..103.5221D}}</ref>

正如其它自由基，它亦是頗活躍。它在水中可電離為S<sup>•−</sup>及H<sup>+</sup>，前者能催化[[脂類]]的順反變換；<ref>{{cite journal|last=Lykakis|first=Ioannis N.|author2=Carla Ferreri |author3=Chryssostomos Chatgilialoglu |date=19 January 2007|title=The sulfhydryl radical (HS<sup>•</sup>/S<sup>•−</sup>): A contender for the isomerization of double bonds in membrane lipids|journal=Angewandte Chemie|volume=46|issue=11|pages=1914–1916|doi=10.1002/anie.200604525|pmid=17450618}}</ref>但它亦與水中的氧氣反應產生SO<sub>2</sub><sup>−</sup>及H<sup>+</sup>，前者繼續與氧氣反應產生[[超氧離子]]及[[二氧化硫]]。<ref name="Dong">{{cite journal|last=Fang|first=Hao Jie|author2=Dong Wen Bo, Zhang Ren Xi and Hou, Hui Qi|date=June 2006|title=水相中·HS 的光谱表征及其与氧气的反应研究|trans-title=Spectrum of<sup>•</sup>HS and its reactions with oxygen in aqueous solution|journal=Acta Physico-Chimica Sinica|volume=22|issue=6|pages=761–763|url=http://www.whxb.pku.edu.cn/EN/abstract/abstract22924.shtml|accessdate=12 October 2011|language=zh|doi=10.3866/PKU.WHXB20060623|archive-date=2020-08-07|archive-url=https://web.archive.org/web/20200807165551/http://www.whxb.pku.edu.cn/EN/abstract/abstract22924.shtml|dead-url=no}}</ref>它與[[羧酸]]反應產生[[羰基硫]]，這更可能是地球大氣層中存在的羰基硫的最大源頭。<ref name=pos/>除此之外也包括與[[乙烯]]反應；與氧氣反應產生羥基自由基及[[一氧化硫]]；與自身反應成氫及硫，或[[二硫化氫]]，<ref>{{cite journal|url=http://kinetics.nist.gov/kinetics/Detail?id=1981TIE/WAM80:0|title=Spectroscopy and reaction kinetics of HS radicals|volume=82|issue=1|pages=80–84|last=Tiee|first=J.J.|journal=Kinetics Database|publisher=NIST|accessdate=13 October 2011|bibcode=1981CPL....82...80T|year=1981|doi=10.1016/0009-2614(81)85111-1|archive-date=2017-11-07|archive-url=https://web.archive.org/web/20171107222041/http://kinetics.nist.gov/kinetics/Detail?id=1981TIE%2FWAM80%3A0|dead-url=no}}</ref>後者再與自由基反應產生硫化氫及[[二硫化一氫]]自由基。<ref name="schippers"/>

== 參考 ==
{{reflist|2}}

[[Category:硫化合物]]
[[Category:氢化物]]
[[Category:自由基]]