Three azo-derivatives: 2, 2′-Dihydroxyazobenzene (DHAB), Sudan Orange G (SOG) and 4-(Phenylazo) diphenylamine (PDA) were studied in this paper from quantum-mechanical and spectral point of view. The nature and the contribution of the intermolecular interactions to the spectral shifts in the solutions of the studied azo-derivatives were established based on the existent theories. Some electro-optical parameters of the studied molecules were calculated with Spartan 14 software using Density Functional Theory (DFT) employing the B3LYP model and the standard 6-31G* basis set. The polarizability and dipole moment in the excited states were estimated considering the variation of the angle between dipole moments in electronic states giving the visible absorption band.

本文从量子力学和光谱角度研究了三种偶氮衍生物：2，2'-二羟基偶氮苯（DHAB），苏丹橙G（SOG）和4-（苯基偶氮）二苯胺（PDA）。基于现有理论建立了偶氮衍生物溶液中分子间相互作用的性质和对光谱位移的贡献。使用B3LYP模型和标准6-31G *基础集，使用密度泛函理论（DFT），使用Spartan 14软件计算了所研究分子的一些电光参数。考虑到给出可见吸收带的电子状态下偶极矩之间的角度变化，估算了激发态下的极化率和偶极矩。