氢硫基自由基

氢硫基自由基是一种自由基,具有一颗氢原子和一颗硫原子。

氢硫基自由基
系统名
Sulfanyl[1] (取代法)

Hydridosulfur(•)[1](加合法)

别名 λ1-Sulfane[2]
一氢化硫
识别
CAS号 13940-21-1  checkY
PubChem 5460613
ChemSpider 4574111
SMILES
 
  • [SH]
InChI
 
  • 1S/HS/h1H
InChIKey PXQLVRUNWNTZOS-UHFFFAOYSA-N
Gmelin 299
ChEBI 29312
性质
化学式 HS
摩尔质量 33.073 g mol−1 g·mol⁻¹
外观 黄色气体[3]
溶解性 产生反应
热力学
ΔfHm298K 139.33 kJ mol−1
S298K 195.63 J K−1 mol−1
相关物质
相关自由基 羟基自由基英语Hydroxyl radical
相关化学品 硫化氢

二硫化氢

若非注明,所有数据均出自标准状态(25 ℃,100 kPa)下。

产生

于1939年加利福尼亚大学玛格丽特·N·刘易斯及约翰·U·怀特首次发现其存在。[4]他们对硫化氢进行射频放电以取得氢硫基自由基,[5]从中观察到对应其2Σ+2Πi跃迁的325 nm吸收线

它亦可于硫化氢以紫外线产生,吸收峰值为190 nm波长的辐射。[6]

硫醇(如乙硫醇)的热分解会产生氢硫基自由基。[7]其亦可由硫酸铈(IV)氧化硫化氢离子(HS)产生。[8]

其在生物的代谢作用中对硫化氢的反应,如进行解毒时也会出现。人体中的SOD1酶英语SOD1可将HS转为HS[9]硫酸盐还原细菌中的黄色素c硫化物脱氢酶英语Flavocytochrome c sulfide dehydrogenase亦能催化硫化氢离子的氧化作用,移除电子并产生该自由基。[10]

当含硫矿物被三价铁离子溶滤时会产生氢硫基自由基离子:

 

该离子其后便让水吸收氢离子而成为氢硫基自由基。上述的M为一种金属,例如铜或锌。[11]此反应亦有发展以生物滤化提炼金属矿物的潜在可能。

自然界的存在

氢硫基自由基由山村一诚等首次于星际空间发现,他们在2000年发表其于仙女座R观测到相关吸收线的文章。[12]它被观测到的紫外谱线分别为:326.0459、327.5468、328.9749、330.0892及330.1112 nm。[13]

它预计是在气态巨行星(如木星)及棕矮星存在的三大含硫气体之一,[14]亦很可能于已冷却恒星中存在。它已在星际气体中探测到,[15]亦可能存在于彗星中。[16]

在地球的大气层中亦有该自由基,由自然发生的(例如光分解作用[17])及由人为除臭引致的硫化氢降解形成。[18]另外,当地球大气层中的羟基自由基英语Hydroxyl radical与硫化氢、二硫化碳羰基硫反应亦会产生氢硫基自由基、二氧化碳和水。这自由基在大气层中有多种反应,如与NO2产生HSNO2及HSONO,后者分解为HSO及NO;亦会与氧气及一氧化二氮反应。[19]其与氯气反应会产生HSCl及Cl自由基;[20]与臭氧反应则产生HSO及氧。[21]

理论上在含有硫化氢的行星大氧层在足够温度及压力下便能分解成自由基。在特定温度及压力下两者比例为:

 

在一个以氢气为主的气态巨行星或恒星,在以下情况氢硫基自由基与硫化氢为同一水平:

 

而在更高温度中自由基会分解成气态硫及氢气,在以下情况它与气态硫为同一水平:

 .

这两条方程会于1509 K及1.51 Pa处相交,在更低的度及压力下该自由基被排除在外。[14]

特性

氢硫基自由基中氢与硫的原子间距为0.134 nm。[22]电离能为10.4219 eV;[23]成为HS的还原电位为0.92 eV。[24]

正如其它自由基,它亦是颇活跃。它在水中可电离为S•−及H+,前者能催化脂类的顺反变换;[25]但它亦与水中的氧气反应产生SO2及H+,前者继续与氧气反应产生超氧离子二氧化硫[26]它与羧酸反应产生羰基硫,这更可能是地球大气层中存在的羰基硫的最大源头。[8]除此之外也包括与乙烯反应;与氧气反应产生羟基自由基及一氧化硫;与自身反应成氢及硫,或二硫化氢[27]后者再与自由基反应产生硫化氢及二硫化一氢自由基。[11]

参考

  1. ^ 1.0 1.1 sulfanyl (CHEBI:29312). Chemical entities of biological interest. UK: European Bioinformatics Institute. Main. 6 November 2006 [8 October 2011]. (原始内容存档于2017-12-27). 
  2. ^ Mercapto radical – Compound summary. PubChem Compound. USA: National Center for Biotechnology Information. Identification and related records. 16 September 2004 [12 October 2011]. 
  3. ^ Zahnle, Kevin; Mark S. Marley; R. S. Freedman; K. Lodders; J. J. Fortney. Atmospheric sulfur photochemistry on hot Jupiters. The Astrophysical Journal. 26 June 2009, 701 (1): L20–L24. Bibcode:2009ApJ...701L..20Z. arXiv:0903.1663v2 . doi:10.1088/0004-637X/701/1/L20. 
  4. ^ Lewis, Margaret; John U. White. The band spectrum of HS. Physical Review. 1939, 55 (10): 894–898. Bibcode:1939PhRv...55..894L. doi:10.1103/PhysRev.55.894. 
  5. ^ Harrison, Jeremy J.; Bryce E. Williamson. Magnetic circular dichroism of the mercapto radical in noble-gas matrices (PDF). Journal of the Indian Institute of Science. November 2005, 85: 391–402 [2019-11-30]. (原始内容 (PDF)存档于2012-04-15). 
  6. ^ Hollaender, Alexander; Livingston, Robert. 1. Radiation Biology. McGraw Hill. 1955: 27. 
  7. ^ Sehon, A. H.; B. deB. Darwent. The thermal decomposition of mercaptans. Journal of the American Chemical Society. October 1954, 76 (19): 4806. doi:10.1021/ja01648a011. 
  8. ^ 8.0 8.1 Pos, Willer H.; Daniel D. Riemer; Rod G. Zika. Carbonyl sulfide (OCS) and carbon monoxide (CO) in natural waters: evidence of a coupled production pathway. Marine Chemistry. 1998, 62 (1–2): 89–101. doi:10.1016/S0304-4203(98)00025-5. 
  9. ^ Lyons, Thomas J.; Edith Butler Gralla; Joan Selverstone Valentine. Biological chemistry of copper-zinc superoxide dismutase and its link to amyotrophic lateral sclerosis (PDF). Metal ions in biological systems (Basel, Switzerland: Marcel Decker Inc). 1999: 139 [10 October 2011]. ISBN 978-0-8247-1956-2. [永久失效链接]
  10. ^ Sorokina, Dimitry Yu; Govardus A.H de Jong; Lesley A. Robertson; Gijs J. Kuenen. Purification and characterization of sulfide dehydrogenase from alkaliphilic chemolithoautotrophic sulfur-oxidizing bacteria. FEBS Letters. 1 May 1998, 427 (1): 11–14. PMID 9613590. doi:10.1016/S0014-5793(98)00379-2. 
  11. ^ 11.0 11.1 Schippers, Axel; Wolfgang Sand. Bacterial leaching of metal sulfides proceeds by two indirect mechanisms via thiosulfate or via polysulfides and sulfur (PDF). Applied and Environmental Microbiology. January 1999, 65 (1): 319–321. PMC 91023 . PMID 9872800. 
  12. ^ Yamamura, Issei; Kawaguchi, K.; Ridgway, S. T. Identification of SH ∆v=1 Ro-vibrational Lines in R Andromedae. The Astrophysical Journal. 2000-1, 258 (1): L33–L36. doi:10.1086/312420. 
  13. ^ Sveta V. Berdyugina & W.C. Livingston. Detection of the mercapto radical SH in the solar atmosphere. Astronomy and Astrophysics. May 2002, 387: L6–L9. Bibcode:2002A&A...387L...6B. doi:10.1051/0004-6361:20020364. 
  14. ^ 14.0 14.1 Visscher, Channon; Katharina Lodders , and Bruce Fegley, Jr.; Fegley, Bruce. Atmospheric chemistry in giant planets, brown dwarfs, and low-mass dwarf stars. II. Sulfur and phosphorus. The Astrophysical Journal. 10 September 2006, 648 (2): 1181–1195. Bibcode:2006ApJ...648.1181V. arXiv:astro-ph/0511136 . doi:10.1086/506245. 
  15. ^ Palca, Joe. Flying telescope makes an out-of-this-world find. NPR. 1 October 2011 [8 October 2011]. (原始内容存档于2020-08-08). 
  16. ^ The cosmic ice laboratory – Cometary molecules. [2019-11-30]. (原始内容存档于2016-12-31). 
  17. ^ Furones, Maikel Yusat Ballester. A theoretical study on the HSO2 molecular system (PDF). Coimbra: Universidade de Coimbra: 1, 37. 2008 [20 October 2011]. (原始内容 (PDF)存档于2012-04-19). 
  18. ^ Mercado-Cabrera, Antonio; B. Jaramillo-Sierra; S.R. Barocio; R. Valencia-Alvarado; M. Pacheco-Pacheco; R. Peña-Eguiluz; R. Lopez-Callejas; A. Muñoz-Castro; A. De la Piedad-Beneitez. Environmental odour control by atmospheric dielectric barrier discharge (PDF). ISPC. 29 April 2009 [20 October 2011]. (原始内容存档 (PDF)于2013-09-27). 
  19. ^ Resende, Stella M. The atmospheric oxidation of the HS radical: Reaction with NO2. Journal of Atmospheric Chemistry. 2007, 56 (1): 21–32. Bibcode:2006JAtC...56...21R. doi:10.1007/s10874-006-9040-z. 
  20. ^ Resende, Stella M.; Fernando R Ornellas. Atmospheric reaction between the HS radical and chlorine. Chemical Physics Letters. 25 February 2000, 318 (4–5): 340–344. Bibcode:2000CPL...318..340R. doi:10.1016/S0009-2614(00)00019-1. 
  21. ^ Yoshimura, Yasunori; Toshio Kasai, Hiroshi Ohoyama and Keiji Kuwata; Ohoyama, Hiroshi; Kuwata, Keiji. Nascent HF + and HSO(2A') formations in the elementary reactions of F + H2S and HS + O3 and the internal energy distributions. Canadian Journal of Chemistry. 1995, 73 (2): 204–221. doi:10.1139/v95-029. 
  22. ^ Ellingson, Benjamin A.; Donald G. Truhlar. Explanation of the unusual temperature dependence of the atmospheric important OH + H2S → H2O + SH reaction and prediction of the rate constant at combustion temperatures (PDF). J. Am. Chem. Soc. 1 August 2007, 129 (42): 12765–12771 [12769] [20 October 2011]. PMID 17910447. doi:10.1021/ja072538b. (原始内容 (reprint)存档于2012-04-25). 
  23. ^ Cheng, B. M.; E. P. Chew, W. C. Hung, J. Eberhard and Y. P. Lee; Hung, Wen-Ching; Eberhard, Jürg; Lee, Yuan-Pern. Photoionization studies of sulfur radicals and products of their reactions (PDF). Journal of Synchrotron Radiation. May 1998, 5 (3): 1041–3. PMID 15263738. doi:10.1107/S0909049597016075. 
  24. ^ Das, T. N.; R. E. Huie; P. Neta; S. Padmaja. Reduction potential of the sulfhydryl radical: pulse radiolysis and laser flash photolysis studies of the formation and reactions of SH and HS–SH•− in aqueous solutions. The Journal of Physical Chemistry A. 11 June 1999, 103 (27): 5221–5226. Bibcode:1999JPCA..103.5221D. doi:10.1021/jp9907544. 
  25. ^ Lykakis, Ioannis N.; Carla Ferreri; Chryssostomos Chatgilialoglu. The sulfhydryl radical (HS/S•−): A contender for the isomerization of double bonds in membrane lipids. Angewandte Chemie. 19 January 2007, 46 (11): 1914–1916. PMID 17450618. doi:10.1002/anie.200604525. 
  26. ^ Fang, Hao Jie; Dong Wen Bo, Zhang Ren Xi and Hou, Hui Qi. 水相中·HS 的光谱表征及其与氧气的反应研究 [Spectrum ofHS and its reactions with oxygen in aqueous solution]. Acta Physico-Chimica Sinica. June 2006, 22 (6): 761–763 [12 October 2011]. doi:10.3866/PKU.WHXB20060623. (原始内容存档于2020-08-07) (中文). 
  27. ^ Tiee, J.J. Spectroscopy and reaction kinetics of HS radicals. Kinetics Database (NIST). 1981, 82 (1): 80–84 [13 October 2011]. Bibcode:1981CPL....82...80T. doi:10.1016/0009-2614(81)85111-1. (原始内容存档于2017-11-07).