电子亲合能
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一元素或化合物 X 的电子亲合能（或电子亲和势或电子亲和力） Eea 等于该物质的 -1 价离子失去一个电子，变成基态原子或化合物时所需吸收的能量。
- X− + Eea → X + e−
X 的电子亲合能越大，它夺取电子的能力（或称“非金属性”）越强，越靠近周期表右侧。氯元素的电子亲合能最大。
其他定义
除以上定义（定义一）之外，电子亲合能还有两种定义方式：
定义二和定义一等价，是将一物质的原子或分子获得一个电子，变成 -1 价离子时放出的能量。此定义下的电子亲合能和定义一相同。不过此定义下，放出能量时电子亲和能为正，吸收能量时电子亲和能为负，正负号的使用和一般热力学的定义恰好相反。
定义三，是将一物质的原子或分子获得一个电子，变成 -1 价离子时的能量变化。[1] 放热时数值为负，吸热时数值为正。定义三的正负号使用和一般热力学的定义相同。但其电子亲合能恰为定义一的负值。
本文采用定义一的电子亲合能。
元素的电子亲合能
并非所有的元素的电子亲合能均为正，电子亲合能为正表示其 -1 价的离子需吸收能量才能变为电中性的原子（早期的教科书写有些元素，例如惰性气体，其电子亲合能为负，此说法并未被现代的化学家接受）。若其阴离子较不稳定，容易变成原子，则其电子亲合能较低。元素中氯的电子亲合能最高，汞和惰气等元素的电子亲合能都接近零。一般来说，非金属的电子亲合能都比金属高。
总的来说，同一周期从左至右，价壳层电子递增，使得原子稳定性上升，原子半径递减，对电子的吸引能力渐强，因而电子亲合能递增；同族元素从上到下，因原子半径的增大，而且总电子数增加，原子稳定性下降，元素电负性值递减。 实际上，随核电荷数递增或同族元素从上到下，电子亲和能的变化并不单调。
电子亲合能(周期表)
下列数据以kJ/mole为单位。带星号的元素在量子力学基态被认为有接近零的电子亲合能。
| 周期 | 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 |
7 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 |
0 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 |
325 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 |
53 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 |
15 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 钅达 |
Rg 钅仑 |
Cn 钅哥 |
Uut |
Fl |
Uup |
Lv |
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 钸 |
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 |
列表及参考资料
| 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). |
| 钾 | 48.38 | Slater et al. (1978). Andersson et al. (2000). |
| 钙 | 2.37 | Petrunin et al. (1996). |
| 钪 | 18(2) | Feigerle, Herman & Lineberger (1981). |
| 钛 | 8.4(7) | Ilin, Sakharov & Serenkov (1987). |
| 钒 | 51 | Hotop & Lineberger (1985). |
| 铬 | 65.2 | Bilodeau, Scheer & Haugen (1998). |
| 铁 | 14.6(3) | Leopold & Lineberger (1986). |
| 钴 | 64.0 | Scheer et al. (1998c). |
| 镍 | 111.6 | Scheer et al. (1998c). |
| 铜 | 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). |
| 铷 | 46.89 | Frey, Breyer & Hotop (1978). |
| 锶 | 5.02 | Andersen et al. (1997). |
| 钇 | 30 | Feigerle, Herman & Lineberger (1981). |
| 锆 | 41 | Hotop & Lineberger (1985). |
| 铌 | 86(2) | Hotop & Lineberger (1985). |
| 钼 | 72.3 | Bilodeau, Scheer & Haugen (1998). |
| 钌 | 101.0 | Norquist et al. (1999). |
| 铑 | 110.3 | Scheer et al. (1998c). |
| 钯 | 54.24 | Scheer et al. (1998c). |
| 银 | 125.86 | Biladeau, Scheer & Haugen (1998). |
| 铟 | 39 | Williams et al. (1998b). |
| 锡 | 107.30 | Scheer et al. (1998a). |
| 锑 | 101.06 | Scheer, Haugen & Beck (1997). |
| 碲 | 190.16 | Hotop & Lineberger (1985). Haeffler et al. (1996b). |
| 碘 | 295 | Moore (1970). |
| 铯 | 45.51 | Slater et al. (1978). Scheer et al. (1998d). |
| 钡 | 13.95 | Petrunin et al. (1995). |
| 镧 | 45(2) | Covington et al. (1998). |
| 铈 | 92(2) | Davis & Thompson (2002a). |
| 铥 | 99(2) | Davis & Thompson (2002b). |
| 镏 | 33 | Davis & Thompson (2001). |
| 钽 | 31 | Hotop & Lineberger (1985). |
| 钨 | 79 | Hotop & Lineberger (1985). Bengali et al. (1992). |
| 锇 | 104.0 | Biladeau & Haugen (2000). |
| 铱 | 150.9 | Biladeau et al. (1999). |
| 铂 | 205.04 | Biladeau et al. (1999). |
| 金 | 222.75 | Hotop & Lineberger (1985). |
| 铊 | 36 | Carpenter, Covington & Thompson (2000). |
| 铅 | 35 | Hotop & Lineberger (1985). |
| 铋 | 90.92 | Biladeau & Haugen (2001). |
分子的电子亲合能
电子亲合能 Eea 的定义也可以延伸到分子。如苯和萘的电子亲合能为负值，而蒽 、菲、芘的电子亲合能为正值。电脑模拟实验证实 hexacyanobenzene C6(CN)6 的电子亲合能较富勒烯要高。[2]
列表及参考资料
| 分子 | 电子亲合能 (kJ/mol) |
参考资料 |
|---|---|---|
| 双原子分子 | ||
| 溴（分子） | 244 | Janousek & Brauman (1979) |
| 氯气 | 227 | Janousek & Brauman (1979) |
| 氟气 | 297 | Janousek & Brauman (1979) |
| 碘（分子） | 246 | Janousek & Brauman (1979) |
| 氧气 | 43 | CRC Handbook |
| 溴化碘 | 251 | Janousek & Brauman (1979) |
| 氯化锂 | 59 | Janousek & Brauman (1979) |
| 一氧化氮 | 2 | Janousek & Brauman (1979) |
| 三原子分子 | ||
| 二氧化氮 | 222 | Janousek & Brauman (1979) |
| 二氧化硫 | 105 | Janousek & Brauman (1979) |
| 多原子分子 | ||
| 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 |
| 六氟化钨 | 264 | CRC Handbook |
| 六氟化铀 | 280 | CRC Handbook |
参见
注释
- ^ http://www.chemguide.co.uk/atoms/properties/eas.html 其定义的电子亲合能均为负值
- ^ 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
参考资料
以下许多参考资料的文章名称会连结至参考资料的本文，不过需要订阅或付费才能阅读。(摘要)会连结到参考资料的摘要，不需付费即可阅读。
- Andersen, H.H.; Petrunin, V.V.; Kristensen, P.; Andersen, T. (1997). "Structural properties of the negative strontium ion: Binding energy and fine-structure splitting". 物理评论 A (Physical Review A) 55:3247–49. 1 摘要
- Andersson, K.T.; Sandstrom, J.; Kiyan, I.Y.; Hanstorp, D.; Pegg, D.J. (2000). "Measurement of the electron affinity of potassium". 物理评论 A (Physical Review A) 62:022503. 摘要
- 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". 美国化学会会志 (Journal of the American Chemical Society) 114:5257–68. ja00039a043.pdf 摘要
- Bilodeau, R.C.; Haugen, H.K. (2000). "Experimental studies of Os−: Observation of a bound-bound electric dipole transition in an atomic negative ion". 物理评论快报（Physical Review Letters) 85:534–37. 1 摘要
- Bilodeau, R.C.; Haugen, H.K. (2001). "Electron affinity of Bi using infrared laser photodetachment threshold spectroscopy". 物理评论 A (Physical Review A) 64:024501. 摘要
- 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". 物理评论 A (Physical Review A) 61:012505. 摘要
- 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". 物理评论 A (Physical Review A) 40:3698–3701. 1 摘要
- Carpenter, D.L.; Covington, A.M.; Thompson J.S. (2000). "Laser Photodetachment Electron Spectroscopy of Tl−". 物理评论 A (Physical Review A) 61:042501. 摘要
- 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". 物理评论快报（Physical Review Letters) 88:073003. 摘要
- Davis, V.T.; Thompson, J.S. (2002b). "Measurement of the electron affinity of thulium". Phys. Rev. A 65:010501. 摘要
- Dellwo, J.; Liu, Y.; Pegg, D.J.; Alton, G.D. (1992). "Near-Threshold Photodetachment of the Li− Ion". 物理评论 A (Physical Review A) 45:1544–47. 1 摘要
- 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. ob=ArticleURL& udi=B6TGC-44CH2G9-5C& user=10& handle=C-WA-A-AW-AW-MsSAYZA-UUW-U-U-AW-U-U-AAZECUVAUW-AAZDUYVEUW-ADBVDZCBU-AW-U& fmt=summary& coverDate=12/31/1981& rdoc=10& orig=browse& srch=#toc#5251#1981#999769996#270874!& cdi=5251&view=c& acct=C000050221& version=1& urlVersion=0& userid=10&md5=9b77fd58e65e977bf40f2096f230307c 摘要
- Frey, P.; Breyer, F.; Hotop, H. (1978). "High Resolutions Photodetachment from the Rubidium Negative Ion around the Rb(5p½) Threshold". J. Phys. B: At. Mol. Opt. Phys. 11:L589–94. 摘要
- Haeffler, G.; Hanstorp, G.; Kiyan, I.; Klinkmüller, A.E.; Ljungblad, U.; Pegg, D.J. (1996a). "Electron affinity of Li: A state-selective measurement". 物理评论 A (Physical Review A) 53:4127–31. 1 摘要
- 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. 摘要
- 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. 摘要
- Lykke, K.R.; Murray, K.K.; Lineberger, W.C. (1991). "Threshold Photodetachment of H−". 物理评论 A (Physical Review A) 43:6104–7. 1 摘要
- 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. ob=ArticleURL& udi=B6TJN-470VCWY-RT& user=10& handle=C-WA-A-ZZ-ZZ-MsSAYVW-UUA-U-U-ZZ-U-U-AAZECUCUZC-AAZDUYCYZC-ADBVYUEYC-ZZ-U& fmt=summary& coverDate=04/02/1988& rdoc=52& orig=browse& srch=#toc#5315#1988#999689998#349206!& cdi=5315&view=c& acct=C000050221& version=1& urlVersion=0& userid=10&md5=6ad26d4a925695cc7a0cd3098b719211 摘要
- 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 d7s2 4F levels in Ru−, including calculated hyperfine structure and M1 decay rates". 物理评论 A (Physical Review A) 59:1896–1902. 1 摘要
- Pekeris, C.L. (1962). "1 1S, 2 1S, and 2 3S States of H−". 物理评论 (Physical Review ) 126:1470–76. 1 摘要
- Petrunin, V.V.; Volstad, J.D.; Balling, P.; Kristensen, K.; Andersen, T. (1995). "Resonant Ionization Spectroscopy of Ba−: Metastable and Stable Ions". 物理评论快报（Physical Review Letters) 75:1911–14. 1 摘要
- Petrunin, V.V.; Andersen, H.H.; Balling, P.; Andersen, T. (1996). "Structural Properties of the Negative Calcium Ion: Binding Energies and Fine-structure Splitting". 物理评论快报（Physical Review Letters) 76:744–47. 1 摘要
- Scheer, M.; Bilodeau, R.C.; Haugen, H.K. (1998). "Negative ion of boron: An experimental study of the 3P ground state". 物理评论快报（Physical Review Letters) 80:2562–65.
- Scheer, M.; Haugen, H.K.; Beck, D.R. (1997). "Single- and Multiphoton Infrared Laser Spectroscopy of Sb−: A Case Study". 物理评论快报（Physical Review Letters) 79:4104–7. 1 摘要
- 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". 物理评论 A (Physical Review A) 58:2844–56. 1 摘要
- Scheer, M.; Bilodeau, RC; Thogresen, J.; Haugen, HK (1998b). "Threshold Photodetachment of Al−: Electron Affinity and Fine Structure". 物理评论 A (Physical Review A) 57:R1493–96. 1 摘要
- 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−".物理评论 A (Physical Review A) 58:2051–62. 1 摘要
- Scheer, M.; Thøgersen, J.; Bilodeau, R.C.; Brodie, C.A.; Haugen, H.K. (1998d). "Experimental Evidence that the 6s6p 3PJ States of Cs− are Shape Resonances". 物理评论快报（Physical Review Letters) 80:684–87. 1 摘要
- Slater, J.; Read, F.H.; Novick, S.E.; Lineberger, W.C. (1978). "Alkali Negative Ions. III. Multichannel Photodetachment of Cs− and K−". 物理评论 A (Physical Review A) 17:201–13. 1 摘要
- Valli, C.; Blondel, C.; Delsart, C. (1999). "Measuring electron affinities with the photodetachment microscope". 物理评论 A (Physical Review A) 59:3809–15. 1 摘要
- 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. 摘要
- 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−". 物理评论 A (Physical Review A) 58:3582–84. 1 摘要
外部链接
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