依达拉奉及其衍生物电子结构特征的理论研究

Theoretical study on the structure of edaravone and its derivatives

采用量子化学密度泛函理论在B3LYP/6-311++G**水平上对依达拉奉及其五类衍生物的电子结构特征进行了理论研究。结果显示,吸电子基使N(1)-C(1′)键键长缩短,供电子基使N(1)-C(1′)键键长增加。电子密度拓扑分析结果显示,meta-OH、meta-NH_2、meta-CH_3的羰基与取代基间存在较强的分子内O…H氢键,键长分别为(0,1722、0.1962、0.2445)nm,键鞍点电荷密度分别为(0.0432、0.0254、0.0112)a.u.,分子内氢键的形成有利于分子的稳定。表观静电势分析显示,ortho-OH、meta-NO_2、para-NO_2的表观正、负电势的程度分别是邻位、间位、对位取代衍生物中最强的,更易于与受体结合。

The structure of edaravone and its derivatives were studied by using the density functional theory （DFT） at the B3LYP/6-311 ＋＋G＊＊ level. The theoretical study demonstrates that the bond length of N（1）-C（1＇） can be shortened by electron-withdrawing groups on the benzene ring, or can be lengthened by electron-donating groups on the benzene ring. Topological properties of electron density clarify that the O...H intramolecular hydrogen bond between the carbonyl group of meta-OH, meta-NH2, or meta-CH3 and the substituent group may stabilize the molecular. The bond lengths are 0.1722 nm, 0.1962 nm, and 0.2445 nm, respectively, while the corresponding charge density at BCP are 0.0432 a.u., 0.0254 a.u., and 0.0112 a.u.. Electrostatic potential mapping demonstrates that ortho-OH, meta-N02, para-N02 have the strongest positive and negative electric potential among the corresponding ortho-, meta-, para-substituted derivatives, so they would be easy to combinate with its receptor.