1-取代-2-羟氨苯并咪唑类化合物是1-取代-2-氨基苯并咪唑衍生物氧化代谢产生的具有强毒性的不稳定中间体.本文运用密度泛函理论(DFT)量子化学方法,计算得到了8种1-取代-2-羟氨苯并咪唑衍生物的电子结构性质.结果表明,取代基团的引入使咪唑环上C-N键长发生明显改变,N原子上负电荷减少;取代基团的引入对偶极矩、垂直电离势、垂直电子亲合能、化学势、电负性和亲电性等都有较为显著的影响,这些电子结构性质与化合物的毒性息息相关.通过计算得到了吸收光谱数据,取代基团的引入使垂直激发能变大,谐振子强度明显减小,最大吸收波长发生蓝移.量子化学结果为1-取代-2-氨基苯并咪唑衍生物的氧化代谢实验研究和毒性机理揭示提供重要信息.
1-Substituted-2-hydroxyaminobenzimidazoles with high toxicity are unstable intermediates potentially produced during the oxidation metabolism of 1-substituted-2-aminobenzimidazoles.The quantum chemical calculation of density functional theory(DFT) has been performed to investigate the electronic structure and properties of eight kinds of 1-substituted-2-hydroxyaminobenzimidazole derivatives.It follows that the substituted groups have significant effects on the C-N bond length and the charge on N atoms of the imidazole ring.In addition,the substituted groups are responsible for the obvious variation of dipole moment,vertical ionization potential,vertical electron affinity,chemical potential,electronegativity,and electronphilicity,which are related to the toxicity of the derivatives.The calculated absorption and excitation spectra indicate that the increase values of vertical transition energy,the decrease of the oscillator strength and the blue shift of the maximum absorption wavelength are observed in the substituted derivatives.The results from the quantum chemical calculation present important information for the experimental investigations on the oxidation metabolism and toxic mechanism of 1-substituted-2-aminobenzimidazole derivatives.