氦合氢离子

氦合氢离子
	系统名; Hydridohelium(1 )
识别
CAS号	17009-49-3
ChemSpider	21106447
SMILES	[HeH ];
Gmelin	2
ChEBI	33688
性质
化学式	HeH ;
摩尔质量	5.01054 g·mol⁻¹
	若非注明，所有数据均出自标准状态（25 ℃，100 kPa）下。

氦合氢离子，又称氦氢分子离子，化学式为HeH，是一种带正电的离子。它首次发现于1925年，通过质子（或氢离子）和氦原子在气相中反应制得。^[2]氦合氢离子是已知最强的布朗斯特质子酸，质子亲和能为177.8 kJ/mol。^[3]有人认为，这种物质可以存在于自然星际物质中。^[4]氦合氢离子是最简单的异核离子，可以与同核的氢分子离子H₂相比较。与H₂不同的是，它有一个永久的键偶极矩，因此更容易表现出光谱特征。^[5]《自然》杂志于2019年发表的研究显示，人类首次在太空中检测到了氦合氢离子。^[6]

性质

HHe不能在凝聚相中制备，因为在凝聚态中它会与所有的阴离子、分子或是原子发生作用。它可以使O₂、NH₃、SO₂、H₂O和CO₂质子化，分别形成O₂H、NH
4、HSO
2、H₃O和 HCO
2^[7]。诸如一氧化氮、二氧化氮、一氧化二氮、硫化氢、甲烷、乙炔、乙烯、乙烷、甲醇和乙腈等分子也会与之反应，不过产物会因为能量太高而直接分解。^[7]但是，可以用盖斯定律预测它在水溶液中的酸性：

HHe(g)	→	H(g)	He(g)	178 kJ/mol	^[3]
HHe(aq)	→	HHe(g)		973 kJ/mol	^[8]
H(g)	→	H(aq)		– 1530 kJ/mol
He(g)	→	He(aq)		19 kJ/mol	^[9]
HHe(aq)	→	H(aq)	He(aq)	– 360 kJ/mol

电离过程–360 kJ/mol的自由能变化相当于pK_a为-63。

HeH中共价键的长度是0.772Å。^[10]

其他的氦氢化物离子均已知或者已在理论上进行了研究。HeH₂已经能被微波光谱观测到，^[11]经计算，它的亲和能为6 kcal/mol，而HeH₃的亲和能为0.1 kcal/mol。^[12]

中性分子

不同于氦合氢离子，氢和氦构成的中性分子在一般情况下很不稳定。但是，它作为一个准分子在激发态时是稳定的，于20世纪80年代中期首次在光谱中观测到。^[13]^[14]^[15]

参考文献

引用

^ hydridohelium(1 ) (CHEBI:33688). Chemical Entities of Biological Interest (ChEBI). UK: European Bioinformatics Institute. [2012-03-13]. （原始内容存档于2019-04-19）.
^ T. R. Hogness and E. G. Lunn. The Ionization of Hydrogen by Electron Impact as Interpreted by Positive Ray Analysis. Physical Review. 1925, 26: 44–55. doi:10.1103/PhysRev.26.44.
^ ^3.0 ^3.1 Lias, S. G.; Liebman, J. F.; Levin, R. D. Evaluated Gas Phase Basicities and Proton Affinities of Molecules; Heats of Formation of Protonated Molecules. Journal of Physical and Chemical Reference Data. 1984, 13: 695. doi:10.1063/1.555719.
^ J. Fernandez; F. Martin. Photoionization of the HeH molecular ion. J. Phys. B: At. Mol. Opt. Phys. 2007, 40: 2471–2480. doi:10.1088/0953-4075/40/12/020.
^ Coxon, J; Hajigeorgiou, PG. Experimental Born–Oppenheimer Potential for theX1Σ Ground State of HeH : Comparison with theAb InitioPotential. Journal of Molecular Spectroscopy. 1999, 193 (2): 306. PMID 9920707. doi:10.1006/jmsp.1998.7740.
^ Stutzki, Jürgen; Risacher, Christophe; Ricken, Oliver; Klein, Bernd; Karl Jacobs; Graf, Urs U.; Menten, Karl M.; Neufeld, David; Wiesemeyer, Helmut. Astrophysical detection of the helium hydride ion HeH . Nature. 2019-04, 568 (7752): 357–359 [2019-04-18]. ISSN 1476-4687. doi:10.1038/s41586-019-1090-x. （原始内容存档于2019-04-18）（英语）.
^ ^7.0 ^7.1 Grandinetti, Felice. Helium chemistry: a survey of the role of the ionic species. International Journal of Mass Spectrometry. October 2004, 237 (2–3): 243–267. Bibcode:2004IJMSp.237..243G. doi:10.1016/j.ijms.2004.07.012.
^ Estimated to be the same as for Li(aq) → Li(g).
^ Estimated from solubility data.
^ Coyne, John P.; Ball, David W. Alpha particle chemistry. On the formation of stable complexes between He2 and other simple species: implications for atmospheric and interstellar chemistry. Journal of Molecular Modeling. 2009, 15 (1): 37. PMID 18936986. doi:10.1007/s00894-008-0371-3.
^ Alan Carrington, David I. Gammie, Andrew M. Shaw, Susie M. Taylor and Jeremy M. Hutson. Observation of a microwave spectrum of the long-range He···H₂ complex. Chemical Physics Letters. 1996, 260: 395–405. doi:10.1016/0009-2614(96)00860-3.
^ F.Pauzat and Y. Ellinger Where do noble gases hide in space? 互联网档案馆的存檔，存档日期2007-02-02., Astrochemistry: Recent Successes and Current Challenges, Poster Book IAU Symposium No. 231, 2005 A. J. Markwick-Kemper (ed.)
^ Thomas Möller, Michael Beland, and Georg Zimmerer. Observation of Fluorescence of the HeH Molecule. Phys. Rev. Lett. 1985, 55 (20): 2145–2148. PMID 10032060. doi:10.1103/PhysRevLett.55.2145.
^ Wolfgang Ketterle. Nobel Prizes. （原始内容存档于2010-12-14）.
^ W. Ketterle, H. Figger, and H. Walther. Emission spectra of bound helium hydride. Phys. Rev. Lett. 1985, 55 (27): 2941–2944. PMID 10032281. doi:10.1103/PhysRevLett.55.2941.

来源

除非另外提及，数据取自Weast, R. C. (Ed.) (1981). CRC Handbook of Chemistry and Physics (62nd Edn.). Boca Raton, FL: CRC Press. ISBN 0-8493-0462-8.

[1] ydridohelium(1 ) (CHEBI:33688). Chemical Entities of Biological Interest (ChEBI). UK: European Bioinformatics Institute. [2012-03-13]. （原始内容存档于2019-04-19）.

[2] T. R. Hogness and E. G. Lunn. The Ionization of Hydrogen by Electron Impact as Interpreted by Positive Ray Analysis. Physical Review. 1925, 26: 44–55. doi:10.1103/PhysRev.26.44.

[Epa-3] 3.0 ^3.1 Lias, S. G.; Liebman, J. F.; Levin, R. D. Evaluated Gas Phase Basicities and Proton Affinities of Molecules; Heats of Formation of Protonated Molecules. Journal of Physical and Chemical Reference Data. 1984, 13: 695. doi:10.1063/1.555719.

[4] J. Fernandez; F. Martin. Photoionization of the HeH molecular ion. J. Phys. B: At. Mol. Opt. Phys. 2007, 40: 2471–2480. doi:10.1088/0953-4075/40/12/020.

[5] Coxon, J; Hajigeorgiou, PG. Experimental Born–Oppenheimer Potential for theX1Σ Ground State of HeH : Comparison with theAb InitioPotential. Journal of Molecular Spectroscopy. 1999, 193 (2): 306. PMID 9920707. doi:10.1006/jmsp.1998.7740.

[6] Stutzki, Jürgen; Risacher, Christophe; Ricken, Oliver; Klein, Bernd; Karl Jacobs; Graf, Urs U.; Menten, Karl M.; Neufeld, David; Wiesemeyer, Helmut. Astrophysical detection of the helium hydride ion HeH . Nature. 2019-04, 568 (7752): 357–359 [2019-04-18]. ISSN 1476-4687. doi:10.1038/s41586-019-1090-x. （原始内容存档于2019-04-18）（英语）.

[Gran004-7] 7.0 ^7.1 Grandinetti, Felice. Helium chemistry: a survey of the role of the ionic species. International Journal of Mass Spectrometry. October 2004, 237 (2–3): 243–267. Bibcode:2004IJMSp.237..243G. doi:10.1016/j.ijms.2004.07.012.

[8] Estimated to be the same as for Li(aq) → Li(g).

[EstSol-9] Estimated from solubility data.

[Coyne-10] Coyne, John P.; Ball, David W. Alpha particle chemistry. On the formation of stable complexes between He2 and other simple species: implications for atmospheric and interstellar chemistry. Journal of Molecular Modeling. 2009, 15 (1): 37. PMID 18936986. doi:10.1007/s00894-008-0371-3.

[11] Alan Carrington, David I. Gammie, Andrew M. Shaw, Susie M. Taylor and Jeremy M. Hutson. Observation of a microwave spectrum of the long-range He···H₂ complex. Chemical Physics Letters. 1996, 260: 395–405. doi:10.1016/0009-2614(96)00860-3.

[12] F.Pauzat and Y. Ellinger Where do noble gases hide in space? 互联网档案馆的存檔，存档日期2007-02-02., Astrochemistry: Recent Successes and Current Challenges, Poster Book IAU Symposium No. 231, 2005 A. J. Markwick-Kemper (ed.)

[13] Thomas Möller, Michael Beland, and Georg Zimmerer. Observation of Fluorescence of the HeH Molecule. Phys. Rev. Lett. 1985, 55 (20): 2145–2148. PMID 10032060. doi:10.1103/PhysRevLett.55.2145.

[14] Wolfgang Ketterle. Nobel Prizes. （原始内容存档于2010-12-14）.

[15] W. Ketterle, H. Figger, and H. Walther. Emission spectra of bound helium hydride. Phys. Rev. Lett. 1985, 55 (27): 2941–2944. PMID 10032281. doi:10.1103/PhysRevLett.55.2941.

[1]

[2]

[3]

[4]

[5]

[6]

[7]

[8]

[9]

[10]

[11]

[12]

[13]

[14]

[15]