用Taftσ~*常数计算基团电负性

CALCULATION OF GROUP ELECTRONEGATIVITY WITH Taft σ *

注意到 Ｔａｆｔ σ常数只包含诱导效应，应与基团电负性之间存在较好的线性关系： Ｘ＝ ０ ．２８ σ ＋ ２ ．１９ ．运用该式求出常见基团的电负性值与 Ｂｒａｔｓｃｈ 基团电负性及诱导效应指数均有较好的对应关系，对组成相同而结构不同的基团较之 Ｂｒａｔｓｃｈ 值有较好的区分性．

The fact that Taft σ * constant concerns only with inductive effects is taken into consideration,thus,it should be found good linear relationship with group electronegativity: X=0.28σ *+2.19 .Group electronegativity calculated from this equation corresponds soundly to Bratsch group electronegativity and the exponent of inductive effects.Also,it shows clear distinctiveness for the groups with same constituents but different structures than Bratsch values do.