【摘要】 <正> 原子负电性的最简单定义是“原子在分子中吸引电子的能力”。近年来 Moffitt的研究认为一个原子可具有一定范围的负电性,换言之,原子负电性的大小系随其价态而定。关于原子负电性的计算,历年来各方已提出数种理论或经验式的方法,Mulliken 曾从原子的离解电势和电子亲和力来量度原子负电性的大小;Malone 曾就键的偶极矩和负电性差而获得二者之间相互的关系;Pauling 则由热化学的实验数据,即所谓键能量而制定原子负电性的标度;刘遵宪首先由原子半径和原子价按经验式来计算原子负电性;随后孙承谔和作者又各自由量子数、原子序、及原子价之间的关系而提出不同的计算式。不久以前,Gordy 指出了原子负电性与原子半径及有效核更多还原

【Abstract】 According to Mulliken’s definition,the atomic electronegativity is closely allied to ionicity.So the electronegativity of an atom in the stable molecule may be considered as the electric poten-tial at the ionic boundary.In other words,the electronegativity of an atom is directly propor-tional to its effective nuclear charge and inversely proportional to its ionic radius.By plottingthis electric potential against Pauling’s electronegativity scale,a linear relationship between themis obtained.From this the author proposes the following equations for the calculation of electrone-gativity:X=0.11 (Z~*e~2)/R+0.64 (1)X=0.20 (Z~*e~2)/r+0.44 (2)where X represents the electronegativity;e,the electric charge;Z~*e,the effective nuclear chargecalculated by Slater’s rule for the one-electron wave function;R,the ionic radius and r,theunivalent ionic radius.R,the ionic radius and r,the univalent ionic radius.But for the atoms with 1s,2sp orbitals as lithium to fluorine which on their ionization only lsorbital remains,we calculate the electronegativity simply from their effective nuclear charge by thefollowing relationship:X=Z~*/1.3 (3)where the figure 1.3 is the value of the effective nuclear charge of lithium.It is apparent thatthe electronegativity of the atom in this group is the relative effective nuclear charge with respectto that of lithium.By comparison with other authors’ data in Table Ⅰ,the results calculated by the above equa-tions are quite satisfactory.更多还原