[edit] Elements

Electron affinity can be defined as either the energy released by adding an electron to a gaseous atom (negative quantity) or the energy required to remove an electron from a gaseous anion (positive quantity). Either convention can be used in practice, but must be consistent. In the Table below, negative values indicate that the anions are more stable than the neutral atoms. The value for neon with this definition would be positive.

Element	Electron affinity (kJ/mol)	References
Hydrogen	-72.77	Pekeris (1962). Lykke, Murray & Lineberger (1991).
Lithium	-59.62	Hotop & Lineberger (1985). Dellwo et al. (1992). Haeffler et al. (1996a).
Boron	-26.99	Scheer, Bilodeau & Haugen (1998).
Carbon	-121.78	Scheer et al. (1998a).
Oxygen	-141.004	Hotop & Lineberger (1985). Blondel (1995). Valli, Blondel & Delsart (1999).
Fluorine	-328.165	Blondel et al. (1989). Blondel, Delsart & Goldfarb (2001).
Sodium	-52.87	Hotop & Lineberger (1985)
Aluminium	-41.86	Scheer et al. (1998b)
Silicon	-134.07	Scheer et al. (1998a). Blondel, Delsart & Goldfarb (2001).
Phosphorus	-72.03	Hotop & Lineberger (1985).
Sulfur	-200.410	Blondel (1995).
Chlorine	-349	Moore (1970).
Potassium	-48.38	Slater et al. (1978). Andersson et al. (2000).
Calcium	-2.37	Petrunin et al. (1996).
Scandium	-18(2)	Feigerle, Herman & Lineberger (1981).
Titanium	-8.4(7)	Ilin, Sakharov & Serenkov (1987).
Vanadium	-51.	Hotop & Lineberger (1985).
Chromium	-65.2	Bilodeau, Scheer & Haugen (1998).
Iron	-14.6(3)	Leopold & Lineberger (1986).
Cobalt	-64.0	Scheer et al. (1998c).
Nickel	-111.6	Scheer et al. (1998c).
Copper	-119.24	Bilodeau, Scheer & Haugen (1998).
Gallium	-41(3)	Williams et al. (1998a).
Germanium	-118.94	Scheer et al. (1998a).
Arsenic	-78.5(7)	Lippa et al. (1998).
Selenium	-194.97	Hotop & Lineberger (1985). Mansour et al. (1988).
Bromine	-342.54	Blondel et al. (1989).
Rubidium	-46.89	Frey, Breyer & Hotop (1978).
Strontium	-5.02	Andersen et al. (1997).
Yttrium	-30.	Feigerle, Herman & Lineberger (1981).
Zirconium	-41.	Hotop & Lineberger (1985).
Niobium	-86(2)	Hotop & Lineberger (1985).
Molybdenum	-72.3	Bilodeau, Scheer & Haugen (1998).
Ruthenium	-101.0	Norquist et al. (1999).
Rhodium	-110.3	Scheer et al. (1998c).
Palladium	-54.24	Scheer et al. (1998c).
Silver	-125.86	Biladeau, Scheer & Haugen (1998).
Indium	-39	Williams et al. (1998b).
Tin	-107.30	Scheer et al. (1998a).
Antimony	-101.06	Scheer, Haugen & Beck (1997).
Tellurium	-190.16	Hotop & Lineberger (1985). Haeffler et al. (1996b).
Iodine	-295	Moore (1970).
Caesium	-45.51	Slater et al. (1978). Scheer et al. (1998d).
Barium	-13.95	Petrunin et al. (1995).
Lanthanum	-45(2)	Covington et al. (1998).
Cerium	-92(2)	Davis & Thompson (2002a).
Thulium	-99(2)	Davis & Thompson (2002b).
Lutetium	-33	Davis & Thompson (2001).
Tantalum	-31	Hotop & Lineberger (1985).
Tungsten	-79	Hotop & Lineberger (1985). Bengali et al. (1992).
Osmium	-104.0	Bilodeau & Haugen (2000).
Iridium	-150.9	Bilodeau et al. (1999).
Platinum	-205.04	Bilodeau et al. (1999).
Gold	-222.75	Hotop & Lineberger (1985).
Thallium	-36	Carpenter, Covington & Thompson (2000).
Lead	-35	Hotop & Lineberger (1985).
Bismuth	-90.92	Bilodeau & Haugen (2001).

[edit] Molecules

Molecule	Electron affinity (kJ/mol)	References
Diatomics
Dibromine	244	Janousek & Brauman (1979)
Dichlorine	227	Janousek & Brauman (1979)
Difluorine	297	Janousek & Brauman (1979)
Diiodine	246	Janousek & Brauman (1979)
Dioxygen	43	CRC Handbook
Iodine bromide	251	Janousek & Brauman (1979)
Lithium chloride	59	Janousek & Brauman (1979)
Nitric oxide	2	Janousek & Brauman (1979)
Triatomics
Nitrogen dioxide	222	Janousek & Brauman (1979)
Sulfur dioxide	105	Janousek & Brauman (1979)
Larger polyatomics
Benzene	−110	Janousek & Brauman (1979)
p-Benzoquinone	129	CRC Handbook
Boron trifluoride	255	CRC Handbook
Nitric acid	59	Janousek & Brauman (1979)
Nitromethane	38	Janousek & Brauman (1979)
Phosphoryl chloride	134	Janousek & Brauman (1979)
Sulfur hexafluoride	138	CRC Handbook
Tetracyanoethylene	278	CRC Handbook
Tungsten hexafluoride	264	CRC Handbook
Uranium hexafluoride	280	CRC Handbook

[edit] References

Many of the links to the full text of articles (linked from article titles) require subscription to the journal or payment. The links to abstracts are usually free of charge.

• Andersen, H.H.; Petrunin, V.V.; Kristensen, P.; Andersen, T. (1997). "Structural properties of the negative strontium ion: Binding energy and fine-structure splitting". Phys. Rev. A 55:3247–49. Abstract
• Andersson, K.T.; Sandstrom, J.; Kiyan, I.Y.; Hanstorp, D.; Pegg, D.J. (2000). "Measurement of the electron affinity of potassium". Phys. Rev. A 62:022503. Abstract
• Bengali, A.A.; Casey, S.M.; Cheng, C.-L.; Dick, J.P.; Fenn, T.; Villaalta, P.W.; Leopold, D.G. (1992). "Negative Ion Photoelectron Spectroscopy of Coordinatively Unsaturated Group VI Metal Carbonyls: Cr(CO)₃, Mo(CO)₃, and W(CO)₃". J. Am. Chem. Soc. 114:5257–68. Abstract
• Bilodeau, R.C.; Haugen, H.K. (2000). "Experimental studies of Os⁻: Observation of a bound-bound electric dipole transition in an atomic negative ion". Phys. Rev. Lett. 85:534–37. Abstract
• Bilodeau, R.C.; Haugen, H.K. (2001). "Electron affinity of Bi using infrared laser photodetachment threshold spectroscopy". Phys. Rev. A 64:024501. Abstract
• Bilodeau, R.C.; Scheer, M.; Haugen, H.K. (1998). "Infrared Laser Photodetachment of Transition Metal Negative Ions: Studies on Cr⁻, Mo⁻, Cu⁻, and Ag⁻". J. Phys. B: At. Mol. Opt. Phys. 31:3885–91.
• Bilodeau, R.C.; Scheer, M.; Haugen, H.K.; Brooks, R.L. (1999). "Near-threshold Laser Spectroscopy of Iridium and Platinum Negative Ions: Electron Affinities and the Threshold Law". Phys. Rev. A 61:012505. Abstract
• Blondel, C. (1995). "Recent experimental achievements with negative ions". Phys. Scr. T58:31.
• Blondel, C.; Delsart, C.; Goldfarb, F. (2001). "Electron spectrometry at the μeV level and the electron affinities of Si and F". J. Phys. B: At. Mol. Opt. Phys. 34:L281–88.
• Blondel, C.; Cacciani, P.; Delsart, C.; Trainham, R. (1989). "High Resolution Determination of the Electron Affinity of Fluorine and Bromine using Crossed Ion and Laser Beams". Phys. Rev. A 40:3698–3701. Abstract
• Carpenter, D.L.; Covington, A.M.; Thompson J.S. (2000). "Laser Photodetachment Electron Spectroscopy of Tl⁻". Phys. Rev. A 61:042501. Abstract
• Covington, A.M.; Calabrese, D.; Thompson, J.S.; Kvale, T.J. (1998). "Measurement of the electron affinity of lanthanum", J. Phys. B: At. Mol. Opt. Phys. 31:L855–60.
• CRC Handbook of Chemistry and Physics (62nd Edn. (1981); Weast, Robert C. (ed)). Boca Raton, FL: CRC Press. "Section E, General Physical Constants; Electron Affinities".
• Davis, V.T.; Thompson, J.S. (2001). "Measurement of the electron affinity of lutetium". J. Phys. B: At. Mol. Opt. Phys. 34:L433–37.
• Davis, V.T.; Thompson, J.S. (2002a). "Measurement of the electron affinity of cerium". Phys. Rev. Lett. 88:073003. Abstract
• Davis, V.T.; Thompson, J.S. (2002b). "Measurement of the electron affinity of thulium". Phys. Rev. A 65:010501. Abstract
• Dellwo, J.; Liu, Y.; Pegg, D.J.; Alton, G.D. (1992). "Near-Threshold Photodetachment of the Li⁻ Ion". Phys. Rev. A 45:1544–47. Abstract
• Feigerle, C.S.; Herman, Z.; Lineberger, W.C. (1981). "Laser Photoelectron Spectroscopy of Sc- and Y-: A Determination of the Order of Electron Filling in Transition Metal Anions". J. Electron Spectrosc. Relat. Phenom. 23:441–50. Abstract
• Frey, P.; Breyer, F.; Hotop, H. (1978). "High Resolutions Photodetachment from the Rubidium Negative Ion around the Rb(5p_½) Threshold". J. Phys. B: At. Mol. Opt. Phys. 11:L589–94. Abstract
• Haeffler, G.; Hanstorp, G.; Kiyan, I.; Klinkmüller, A.E.; Ljungblad, U.; Pegg, D.J. (1996a). "Electron affinity of Li: A state-selective measurement". Phys. Rev. A 53:4127–31. Abstract
• Haeffler, G.; Klinkmüller, A.E.; Rangell, J.; Berzinsh, U.; Hanstorp, D. (1996b). "The Electron Affinity of Tellurium". Z. Phys. D 38:211.
• Hotop, H.; Lineberger, W.C. (1985). "Binding energies in atomic negative ions. II". J. Phys. Chem. Ref. Data 14:731.
• Ilin, R.N.; Sakharov, V.I.; Serenkov, I.T. (1987). "Study of Titanium Negative Ion Using Method of Electron Detachment by an Electric Field". Opt. Spectros. (USSR) 62:578.
• Janousek, B. K.; Brauman, J. I. (1979). in Gas Phase Ion Chemistry (Bowers, M. T. (Ed.)), Vol. 2. New York: Academic Press. p. 53.
• Leopold, D.G.; Lineberger, W.C. (1986). "A study of the low-lying electronic states of Fe₂ and Co₂ by negative ion photoelectron spectroscopy". J. Chem. Phys. 85:51–55. Abstract
• Lippa, T.P.; Xu, S.J.; Lyapustina, S.A.; Nilles, J.M.; Bowen, K.H. (1998) "Photoelectron spectroscopy of As⁻, As₂⁻, As₃⁻, As₄⁻, and As₅⁻". J. Chem. Phys. 109:10727–31. Abstract
• Lykke, K.R.; Murray, K.K.; Lineberger, W.C. (1991). "Threshold Photodetachment of H⁻". Phys. Rev. A 43:6104–7. Abstract
• Mansour, N.B.; Edge, C.J.; Larson, D.J. (1988). "Laser Photodetachment Spectroscopy of Se⁻ and S⁻". Nucl. Instrum. Meth. Phys. Res. B 31:313–16. Abstract
• Moore, C.E. (1970). National Standard Reference Data Series 34, Washington: National Bureau of Standards, U.S. Government Printing Office.
• Norquist, P.L.; Beck, D.R.; Bilodeau, R.C.; Scheer, M.; Srawley, R.A.; Haugen, H.K. (1999). "Theoretical and experimental binding energies for the d⁷s^{2 4}F levels in Ru⁻, including calculated hyperfine structure and M1 decay rates". Phys. Rev. A 59:1896–1902. Abstract
• Pekeris, C.L. (1962). "1 ¹S, 2 ¹S, and 2 ³S States of H⁻". Phys. Rev. 126:1470–76. Abstract
• Petrunin, V.V.; Volstad, J.D.; Balling, P.; Kristensen, K.; Andersen, T. (1995). "Resonant Ionization Spectroscopy of Ba⁻: Metastable and Stable Ions". Phys. Rev. Lett. 75:1911–14. Abstract
• Petrunin, V.V.; Andersen, H.H.; Balling, P.; Andersen, T. (1996). "Structural Properties of the Negative Calcium Ion: Binding Energies and Fine-structure Splitting". Phys. Rev. Lett. 76:744–47. Abstract
• Scheer, M.; Bilodeau, R.C.; Haugen, H.K. (1998). "Negative ion of boron: An experimental study of the ³P ground state". Phys. Rev. Lett. 80:2562–65.
• Scheer, M.; Haugen, H.K.; Beck, D.R. (1997). "Single- and Multiphoton Infrared Laser Spectroscopy of Sb⁻: A Case Study". Phys. Rev. Lett. 79:4104–7. Abstract
• Scheer, M.; Bilodeau, R.C.; Brodie, C.A.; Haugen, H.K. (1998a). "Systematic study of the stable states of C⁻, Si⁻, Ge⁻, and Sn⁻ via infrared laser spectroscopy". Phys. Rev. A 58:2844–56. Abstract
• Scheer, M.; Bilodeau, RC; Thogresen, J.; Haugen, HK (1998b). "Threshold Photodetachment of Al⁻: Electron Affinity and Fine Structure". Phys. Rev. A 57:R1493–96. Abstract
• Scheer, M.; Brodie, C.A.; Bilodeau, R.C.; Haugen, H.K. (1998c). "Laser spectroscopic measurements of binding energies and fine-structure splittings of Co⁻, Ni⁻, Rh⁻, and Pd⁻". Phys. Rev. A 58:2051–62. Abstract
• Scheer, M.; Thøgersen, J.; Bilodeau, R.C.; Brodie, C.A.; Haugen, H.K. (1998d). "Experimental Evidence that the 6s6p ³P_J States of Cs⁻ are Shape Resonances". Phys. Rev. Lett. 80:684–87. Abstract
• Slater, J.; Read, F.H.; Novick, S.E.; Lineberger, W.C. (1978). "Alkali Negative Ions. III. Multichannel Photodetachment of Cs⁻ and K⁻". Phys. Rev. A 17:201–13. Abstract
• Valli, C.; Blondel, C.; Delsart, C. (1999). "Measuring electron affinities with the photodetachment microscope". Phys. Rev. A 59:3809–15. Abstract
• Williams, W.W.; Carpenter, D.L.; Covington, A.M.; Koepnick, M.C.; Calabrese, D.; Thompson, J.S. (1998a). "Laser photodetachment electron spectrometry of Ga⁻". J. Phys. B: At. Mol. Opt. Phys. 31:L341–45. Abstract
• Williams, W.W.; Carpenter, D.L.; Covington, A.M.; Thompson, J.S.; Kvale, T.J.; Seely, D.G. (1998b). "Fine-Structure-Resolved Laser Photodetachment Electron Spectroscopy of In⁻". Phys. Rev. A 58:3582–84. Abstract