摘要
基于密度泛函理论(DFT)b3lyp/6-31g(d,p)方法的量子化学计算结果,进行了腐植酸(HA)模型结构和若干抗氧化剂反应活性指数的比较研究。以15种物质为例,发现电负性指数χ与最低未占据分子轨道的能量(E_(LUMO))呈线性相关,R^(2)=0.977。HA(E_(LUMO)=–2.52)与分子O_(2)(E_(LUMO)=–3.07)紧密靠近,这一事实表明这个天然物质具有很高的电负性。本文提出通过分子O_(2)的吸附能来评价有机物HA的抗氧化能力。通过量子化学方法pm6确定HA不同部位O_(2)传感能量的局部最小值,确定了O_(2)被羟基吸附的能量ΔE_(ads)=–70 kcal/mol。结果显示:HA高反应活性的有机部分能够抑制氧化过程中的分子O_(2)。
A comparative analysis of the reactivity indices of the model structure of humic acid(HA) and a number of antioxidants was carried out based on the results of quantum-chemical calculations performedusing the density functional theory (DFT) b3lyp/6-31g (d,p) method.With the use of 15 compounds as an example,it was found that the electronegativity indexχlinearly correlates with the energy of the lowest unoccupied molecular orbital (E_(LUMO)),R^(2)=0.977.HA (E_(LUMO)=–2.52) are located close to molecular oxygen (E_(LUMO)=–3.07),and this fact indicates a high electronegativity of these natural compounds.It was proposed to evaluate the antioxidant ability of the organic matter of HA by the adsorption energy of molecular oxygen.By determining the local minima of O_(2) sensing energy in diff erent sections of HA using the pm6 quantum chemical method,it was established that oxygen is adsorbed by a hydroxyl group with the energy ΔE_(ads)=–70 kcal/mol.This allows the highly reactive of HA to inhibit molecular oxygen in oxidation processes.
作者
T.A.Yarkova
A.M.Gyul'maliev
沈天瑞(译)
周霞萍(译)
T.A.Yarkova;A.M.Gyul'maliev;Shen Tianrui;Zhou Xiaping(Razumovsky Moscow State University of Technologies and Management,Moscow,Russian,123110;Topchiev Institute of Petrochemical Synthesis,Russian Academy of Sciences,Moscow,Russian,119999;Shanghai Zhen derivative Technology Co.Ltd.,Shanghai,201700)
出处
《腐植酸》
2022年第6期62-66,共5页
Humic Acid
关键词
腐植酸
自由基引发剂和抑制剂
抗氧化剂
电子结构的量子化学计算
反应活性指数
humic acid
free radical initiators and inhibitors
antioxidants
quantum-chemical calculations of electronic structure
reactivity indices
