论文部分内容阅读
本文提出了予测稠苯芳杂环及其烷基链上质子化学位移的计算方法。 将稠苯芳杂环化合物用凯库勒式表示,计算式为:为需考虑的苯环内的乙烯基效应。δ为各苯环的环流效应。δ_(1,He)为各芳杂环的屏蔽效应,对杂环上质子它就是该单独芳杂环上相应质子的δ值,对苯环上质子要将它分解为各结构因素的效应,即:σ_(1,He)=(1/2)~(d-1)δ_(x=y)(或δ_2)+σ_(c=d)σ_(m,He)σ_(x-y)与σ_2为杂原子或其基团的屏蔽效应,σ为存在于芳杂环中的乙烯基的效应,σ_(m,He)为芳杂环的环流效应,d为对不同质子所考虑的键数。有取代基时需考虑取代基的效应。计算环上烷基质子的公式为: δ=σ_p,CH_3+ασCH_3+σβCH_3+σGσ.G为稠苯芳杂环基的某级效应。
In this paper, we propose a method for the calculation of protonated chemical shifts of condensed benzene rings and their alkyl chains. The condensed benzene aromatic heterocyclic compounds using Keflar formula, the formula is: to consider the benzene ring within the vinyl effect. δ is the circulation effect of each benzene ring. δ_ (1, He) is the shielding effect of each aromatic heterocyclic ring. For the proton on the heterocyclic ring, which is the δ value of the corresponding proton on the aromatic ring, it is necessary to decompose the proton on the benzene ring into the structural factors. That is, σ_ (1, He) = (1/2) ~ (d-1) δ_ (x = y) (or δ_2) + σ_ (c = d) σ_ (m, He) σ_ (xy) The shielding effect of heteroatoms or their groups, σ is the effect of vinyl groups present in the aromatic heterocycle, σ_ (m, He) is the circulating effect of the aromatic heterocycle, and d is the number of bonds considered for different protons. Substituents need to consider the effect of substituents. The formula for calculating the alkyl protons on the ring is: δ = σ_p, CH_3 + ασCH_3 + σβCH_3 + σGσ.G is a certain level effect of a condensed benzene aromatic heterocyclic group.