取代基性质对苯轮烯电子结构影响的理论研究

Theoretical Study on the Effect of Substituting Group on the Electrnic Spectrum of the Derivatives of [15] dehydrobenzoannulene

运用量子化学中的密度泛函和含时密度泛函理论法,计算了苯[15]轮烯分子1号位被CH3、NH2、OH、Cl、CN和NO2取代后的衍生物几何构型、电子结构、前线分子轨道和电子光谱性质。计算结果表明取代基性质的改变,对苯[15]轮烯的键长和键角等结构参数的影响不大,这与轮烯具有较强的共轭性有关。在1号位取代时,NO2取代物的最大吸收波长红移最多。主要是因为对LUMO轨道而言,硝基取代物的LUMO轨道电子云在硝基附近分布较多。

By means of DFT/B3LYP method, the structure of [15]dehydrobenzoannulene and its six derivatives substituted by Cl43, NH2, OH, Cl, CN and NO2 group at position I were studied using density functional theory and time-dependent density functional theory of quantum chemical. The geometric structures, electronic structure ,frontier molecular orbital and electronic absorption spectrum of the compounds, were investigated. The results showed these structures of derivatives are Little effected when different substituting groups were replaced, when the [15]dehydrobenzoannulene was replaced by NO2, the maximum absorption wavelength blue shifted; the main reason is the lowest unoccupied molecular orbit（LUMO）energy level.