The covalent potential: a simple and useful measure of the valence-state electronegativity for correlating molecular energetics
The covalent potential: a simple and useful measure of the valence-state electronegativity for correlating molecular energetics
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DOI：
10.1021/ar00020a008
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发表时间：
1992-08
影响因子：
18.3
通讯作者：
Yu Luo;S. Benson
中科院分区：
文献类型：
--
作者：
Yu Luo;S. Benson
电负性是化学中最基本、最古老的概念之一，在物理学、生物学和地质学中也有广泛的应用。1，2诺贝尔奖获得者L. Pauling 3”5是第一个制定EN量表的人。[6]他将EN定义为“分子中原子吸引电子的能力”[7]，将键极性定义为两个键合原子之间EN值的差异。鲍林量表是一种半定量量表。当它与某些物理和化学性质相关时，出现了一些意想不到的例外和争议。艾伦®查阅了从1932年到1989年初讨论或评论EN的上千篇文本、综述论文和期刊文章。在最近的一份出版物中，可以找到鲍林和鲍林式的、非经验的以及绝对的EN的有用摘要。[2]我们的兴趣是分子能量学。我们已经作出了努力，通过现有的规模的原子和集团EN相关的生成热。广泛使用的标度，如Pauling，Mulliken，9，10和Allred-Rochow，11没有给出±1 kcal/mol平均值的相关性。不太广泛使用的量表，如Gordy，12，13 Sanderson，14”19 Huheey，20，21艾伦，22 Zhang，23 Mullay，24”26和Inamo-to，27”29的量表并不好。非经验的和绝对的尺度，30”33如FSGO，34 Boyd，35，36和塔夫脱，37，38也导致了困难。鲍林标度最初来自于双原子和简单分子的生成热或键能的实验数据。理论尺度虽然非常复杂，但无助于定量地关联分子能量学。
Electronegativity (EN) is one of themost basic and oldest concepts in chemistry and is also widely used in physics, biology, and geology. 1, 2 Nobel laureate L. Pauling3" 5 was the first person to develop a scale of EN. 6 He defined EN as “the power of an atom in a molecule to attract electrons to itself” 7 and bond polarity as the difference in EN values between two bonded atoms. Pauling’s scale is a semiquantitative scale. There are some unexpected exceptions and controversies when it is correlated with some physical and chemical proper-ties. Allen® reviewed a thousand-odd texts, review papers, and journal articles which discussed or commented on EN from 1932 to early 1989. A useful summary of Pauling and Pauling-like, nonempirical as well as ab-solute EN may be found in a recent publication. 2 Our own interest is in molecular energetics. We have made efforts to correlateheats of formation by means of available scales of atomic and group EN. The scales which are widely used, such as Pauling’s, Mulliken’s, 9, 10 and Allred-Rochow’s, 11 do not give correlation to an average of±1 kcal/mol. Scales which have been less widely used, such as those by Gordy, 12, 13 Sanderson, 14" 19 Huheey, 20, 21 Allen, 22 Zhang, 23 Mullay, 24" 26 and Inamo-to, 27" 29 are not better. The nonempirical and absolute scales, 30" 33 such as FSGO, 34 Boyd, 35, 36 and Taft, 37, 38 have also led to difficulties. Pauling’s scale was initially derived from experimental data on heats of formation or bond energies of diatomic and simple molecules. The theoretical scales, although very sophisticated, do not help to correlate molecular energetics quantitatively.