电子亲合能

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电子亲和能,或者,电子亲和势 元素X的电子亲和能等于该元素的一个气态原子从基态得到一个电子变成-1价离子所需吸收(某些书定义为放出)的能量,多以eV作单位. 若X元素的电子亲和能的绝对值越大,这X的夺取电子能力越强,或曰,非金属性越强,周期表中越向右电子亲和能的值越大,氯元素的电子亲和能最大

电子亲和能, E_ea, of an atom or molecule is the energy required to detach an electron from a singly charged negative ion, i.e., the energy change for the process

X^- → X + e^-

An equivalent definition is the energy released (E_initial − E_final) when an electron is attached to a neutral atom or molecule. It should be noted that the sign convention for E_ea is the opposite to most thermodynamic quantities: a positive electron affinity indicates that energy is released on going from atom to anion.

All elements have a positive electron affinity, but older texts mistakenly report that some elements such as inert gases have negative E_ea, meaning they would repel electrons. This is not recognized by modern chemists. Atoms whose anions are relatively more stable than neutral atoms have a smaller E_ea. Chlorine most strongly attracts extra electrons; mercury most weakly attracts an extra electron. E_ea of noble gases are close to 0.

Although E_ea vary in a chaotic manner across the table, some patterns emerge. Generally, nonmetals have more positive E_ea than metals.

目录 1 元素的电子亲合能 1.1 元素 2 分子 3 周期趋势 4 分子电子亲合能 5 参见 6 参考资料 7 外部链接

[编辑] 元素的电子亲合能

下列数据以kJ/mole为单位。带星号的元素在量子力学基泰被认为有接近零的电子亲合能。

週期

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

电子层

Ｏ族电子数

族

I A

0

1

73 H 氢

* He 氦

K

2

II A

III A

IV A

V A

VI A

VII A

2

60 Li 锂

* Be 铍

27 B 硼

122 C 碳

* N 氮

141 O 氧

328 F 氟

* Ne 氖

L K

8 2

3

53 Na 钠

* Mg 镁

42 Al 铝

134 Si 硅

72 P 磷

200 S 硫

349 Cl 氯

* Ar 氩

M L K

8 8 2

III B

IV B

V B

VI B

VII B

VIII

I B

II B

4

48 K 钾

2 Ca 钙

18 Sc 钪

8 Ti 钛

51 V 钒

65 Cr 铬

* Mn 锰

15 Fe 铁

64 Co 钴

112 Ni 镍

119 Cu 铜

* Zn 锌

41 Ga 镓

119 Ge 锗

79 As 砷

195 Se 硒

343 Br 溴

* Kr 氪

N M L K

8 18 8 2

5

47 Rb 铷

5 Sr 锶

30 Y 钇

41 Zr 锆

86 Nb 铌

72 Mo 钼

* Tc 锝

101 Ru 钌

110 Rh 铑

54 Pd 钯

126 Ag 银

* Cd 镉

39 In 铟

107 Sn 锡

101 Sb 锑

190 Te 碲

295 I 碘

* Xe 氙

O N M L K

8 18 18 8 2

6

46 Cs 铯

14 Ba 钡

镧系

Hf 铪

31 Ta 钽

79 W 钨

* Re 铼

104 Os 锇

150 Ir 铱

205 Pt 铂

223 Au 金

* Hg 汞

36 Tl 铊

35 Pb 铅

91 Bi 铋

Po 钋

At 砹

* Rn 氡

P O N M L K

8 18 32 18 8 2

7

Fr 钫

Ra 镭

锕系

Rf 钅卢

Db 钅杜

Sg 钅喜

Bh 钅波

Hs 钅黑

Mt 钅麦

Ds 鐽

Rg 錀

Uub

Uut

Uuq

Uup

Uuh

Uus

Uuo

镧系元素

45 La 镧

92 Ce 铈

Pr 镨

Nd 钕

Pm 钷

Sm 钐

Eu 铕

Gd 钆

Tb 铽

Dy 镝

Ho 钬

Er 铒

99 Tm 铥

Yb 镱

33 Lu 镥

锕系元素

Ac 锕

Th 钍

Pa 镤

U 铀

Np 錼

Pu 鈽

Am 鋂

Cm 锔

Bk 鉳

Cf 锎

Es 锿

Fm 镄

Md 钔

No 锘

Lr 铹

碱金属	碱土金属	镧系元素	锕系元素	过渡金属
主族金属	类金属	非金属	卤素	稀有氣體

[编辑] 元素

元素	电子亲合能 (kJ/mol)	参考资料
氢	72.77	Pekeris (1962). Lykke, Murray & Lineberger (1991).
锂	59.62	Hotop & Lineberger (1985). Dellwo et al. (1992). Haeffler et al. (1996a).
硼	26.99	Scheer, Bilodeau & Haugen (1998).
碳	121.78	Scheer et al. (1998a).
氧	141.004	Hotop & Lineberger (1985). Blondel (1995). Valli, Blondel & Delsart (1999).
氟	328.165	Blondel et al. (1989). Blondel, Delsart & Goldfarb (2001).
钠	52.87	Hotop & Lineberger (1985)
铝	41.86	Scheer et al. (1998b)
硅	134.07	Scheer et al. (1998a). Blondel, Delsart & Goldfarb (2001).
磷	72.03	Hotop & Lineberger (1985).
硫	200.410	Blondel (1995).
氯	349	Moore (1970).
鉀	48.38	Slater et al. (1978). Andersson et al. (2000).
钙	2.37	Petrunin et al. (1996).
鈧	18(2)	Feigerle, Herman & Lineberger (1981).
钛	8.4(7)	Ilin, Sakharov & Serenkov (1987).
釩	51	Hotop & Lineberger (1985).
鉻	65.2	Bilodeau, Scheer & Haugen (1998).
铁	14.6(3)	Leopold & Lineberger (1986).
鈷	64.0	Scheer et al. (1998c).
鎳	111.6	Scheer et al. (1998c).
銅	119.24	Bilodeau, Scheer & Haugen (1998).
镓	41(3)	Williams et al. (1998a).
锗	118.94	Scheer et al. (1998a).
砷	78.5(7)	Lippa et al. (1998).
硒	194.97	Hotop & Lineberger (1985). Mansour et al. (1988).
溴	342.54	Blondel et al. (1989).
銣	46.89	Frey, Breyer & Hotop (1978).
鍶	5.02	Andersen et al. (1997).
釔	30	Feigerle, Herman & Lineberger (1981).
鋯	41	Hotop & Lineberger (1985).
鈮	86(2)	Hotop & Lineberger (1985).
鉬	72.3	Bilodeau, Scheer & Haugen (1998).
釕	101.0	Norquist et al. (1999).
銠	110.3	Scheer et al. (1998c).
鈀	54.24	Scheer et al. (1998c).
银	125.86	Biladeau, Scheer & Haugen (1998).
銦	39	Williams et al. (1998b).
錫	107.30	Scheer et al. (1998a).
銻	101.06	Scheer, Haugen & Beck (1997).
碲	190.16	Hotop & Lineberger (1985). Haeffler et al. (1996b).
碘	295	Moore (1970).
銫	45.51	Slater et al. (1978). Scheer et al. (1998d).
鋇	13.95	Petrunin et al. (1995).
鑭	45(2)	Covington et al. (1998).
鈰	92(2)	Davis & Thompson (2002a).
銩	99(2)	Davis & Thompson (2002b).
鎦	33	Davis & Thompson (2001).
鉭	31	Hotop & Lineberger (1985).
钨	79	Hotop & Lineberger (1985). Bengali et al. (1992).
鋨	104.0	Biladeau & Haugen (2000).
銥	150.9	Biladeau et al. (1999).
铂	205.04	Biladeau et al. (1999).
金	222.75	Hotop & Lineberger (1985).
鉈	36	Carpenter, Covington & Thompson (2000).
铅	35	Hotop & Lineberger (1985).
鉍	90.92	Biladeau & Haugen (2001).

[编辑] 分子

分子	电子亲合能 (kJ/mol)	参考资料
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
溴化碘	251	Janousek & Brauman (1979)
氯化鋰	59	Janousek & Brauman (1979)
一氧化氮	2	Janousek & Brauman (1979)
Triatomics
二氧化氮	222	Janousek & Brauman (1979)
二氧化硫	105	Janousek & Brauman (1979)
Larger polyatomics
苯	−110	Janousek & Brauman (1979)
1,4-苯二酮	129	CRC Handbook
三氟化硼	255	CRC Handbook
硝酸	59	Janousek & Brauman (1979)
硝基甲烷	38	Janousek & Brauman (1979)
三氯化磷	134	Janousek & Brauman (1979)
六氟化硫	138	CRC Handbook
四氰乙烯	278	CRC Handbook
六氟化鎢	264	CRC Handbook
六氟化鈾	280	CRC Handbook

[编辑] 周期趋势

E_ea increases across a period (row) (since the radius slightly decreases, because of the increased attraction from the nucleus, and the number of electrons in the top shell increases, helping the atom reach maximum stability) in the periodic table and decrease going down a group (family) (because of a large increase in radius and number of electrons that decrease the stability of the atom, repulsing each other).

[编辑] 分子电子亲合能

E_ea is not limited to the elements but also applies to molecules. For instance the electron affinity for benzene is negative, as it that of naphthalene, while those of anthracene,phenanthrene and pyrene are positive. In silico experiments show that the electron affinity of hexacyanobenzene surpasses that of fullerene ^[1].

[编辑] 参见

• Koopmans' theorem
• One-electron reduction
• 电离势
• 电负性
• 价电子

[编辑] 参考资料

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]

1. ↑ Remarkable electron accepting properties of the simplest benzenoid cyanocarbons: hexacyanobenzene, octacyanonaphthalene and decacyanoanthracene Xiuhui Zhang, Qianshu Li, Justin B. Ingels, Andrew C. Simmonett, Steven E. Wheeler, Yaoming Xie, R. Bruce King, Henry F. Schaefer III and F. Albert Cotton Chemical Communications, 2006, 758 - 760 Abstract

[编辑] 外部链接

• Electron affinity, definition from the IUPAC Gold Book
• Article about Electron Affinity