基团电负性研究(VⅢ)—基团电负性与CH_3X/HX的生成热之差

Study on the Group Electronegativity (VIII)——Group Electronegativity and the Differences in Heats of Formation between Hydrogen and Methyl Derivatives

通过研究△△μ(CH_3/HX)与基团x的电负性X_G的内在关系,本文发现了经验方程:△△μ(CH_3X/HX)/P=6．05X_G-16．08这里,△△μ(CH_3/HY)=△μ(CH_3X)-△μ(HX);p为HX分子中氢原子的个数;X_G是作者前一工作的基团电负性．利用上式,我们估算了一些甲基衍生物CH_3X (X=F、 OH、NH_2.Cl. Br. SH 、CH_3 I、SIH_3、PH_2、SnH_3 、AsH_2、SeH)的标准生成热,其平均偏差为0．83Kcal/Mol．同时.导出了一个由△μ(HX)和X_G计算烷基衍生物生成热的方法:△_fH (RX)=△_fH (HX) + (6.05-3.58M^(1/m+0.99)xG-16.08p-1.125m^+2.16式中,m为烷基R结构参数,其它与前式相同。利用上式计算了22个烷基衍生物的生成热,其平均偏差为0.87kcal/mol.

We found a new empirical equation: △△fH. (CH3X / HX) / p = 6.05xG-l6.08 Here, △△fH (CH3X/ HX) = △fH* (CH3X) -△fH (HX), p is the num- ber of hydrogen atom in the HX molecule, XG is group electronegativity proposed by our previous work.Heats of some methyl derivatives RX (X=F、OH、NH2、Cl、Br、 SH、CH3、 I、SiH3. PH2、SnH3、 AsH2、 SeH) are estimated by above formula with average deviations of 0.83 kcal/mo1.Besides, this paper has built up a formuta for calcu- lating the standard heats of formation of alkyl derivative with △fH°(HX) and XG: △fH° (RX) =△fH° (HX) + (6.05p-3.58m.99) XG-16.08p-1.l25m2+2.l6 here, m is the parameter of alkyl structure. For the 22 alkyl derivatives available average deviations are 0.87 kcal /mol.