This study presents a computational investigation of p-phenylenediamine (PPD) interaction with 3,5-dinitrosalicylic acid (DNS) within PPD/DNS charge transfer (CT) complex. All calculations were performed by M06-2X/6-311+G(d,p) levels of theory in vacuum, water and methanol. EDA analysis was used to control the complexation process and suggested that electrostatic and dispersion energies contributes greatly in stabilizing PPD/DNS CT complex. The results of energy optimization showed that PPD/DNS CT complex is stable with negative complexation energy; the obtained geometries showed that ammonium group of PPD is closed to carboxylate one of DNS enabling the establishment of large number of interactions. Additionally, different analyses were performed on obtained optimized structures: TD-DFT, NBO, QTAIM and NCI. Consequently, NBO, QTAIM and NCI analysis give that PPD/DNS CT complex is stabilized by hydrogen bonding and van der Waals interactions.

中文翻译：

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对苯二胺和 3,5-二硝基水杨酸之间电荷转移络合物形成的 DFT 研究

本研究对 PPD/DNS 电荷转移 (CT) 复合物中的对苯二胺 (PPD) 与 3,5-二硝基水杨酸 (DNS) 的相互作用进行了计算研究。所有计算均通过 M06-2X/6-311+G(d,p) 理论水平在真空、水和甲醇中进行。EDA 分析用于控制络合过程，并表明静电和色散能对稳定 PPD/DNS CT 复合物有很大贡献。能量优化结果表明，PPD/DNS CT复合物稳定，复合能量为负；获得的几何结构表明，PPD 的铵基团与 DNS 之一发生羧化，从而能够建立大量的相互作用。此外，对获得的优化结构进行了不同的分析：TD-DFT、NBO、QTAIM 和 NCI。因此，NBO，