Triazoles, nitrogen-containing heterocycles, have gained attention for their applications in medicinal chemistry, drug discovery, agrochemicals, and material sciences. In the current study, we synthesized novel derivatives of N-substituted 2-((5-(3-bromophenyl)-4-methyl-4H-1,2,4-triazol-3-yl)thio)-N-phenylpropanamide and conducted a comprehensive investigation using density functional theory (DFT). These novel structural hybrids of 1,2,4-triazole were synthesized through the multi-step chemical modifications of 3-bromobenzoic acid (1). Initially, compound 1 was converted into its methyl-3-bromobenzoate (2) which was then transformed into 3-bromobenzohydrazide (3). The final step involved the cyclization of compound 3, producing its 1,2,4-triazole derivative (4). This intermediate was then coupled with different electrophiles, resulting in the formation of the final derivatives (7a–7c). Additionally, the characterization of these triazole-based compounds (7a, 7b, and 7c) were carried out using techniques such as IR, HNMR, and UV–visible spectroscopy to understand their structural and spectroscopic properties. The DFT study utilized M06/6-311G(d,p) functional to investigate geometrical parameters, HOMO–LUMO energies, natural bond orbital analyses, transition density matrix (TDM), density of states, and nonlinear optical (NLO) properties. The FMO analysis revealed that compound 7c exhibited the lowest band gap value (4.618 eV). Notably, compound 7c exhibited significant linear polarizability (4.195 > × 10^–23) and first and second hyperpolarizabilities (6.317 > × 10^–30, 4.314 × 10^–35), signifying its potential for nonlinear optical applications. These NLO characteristics imply that each of our compounds, especially 7c, plays a crucial part in fabricating materials showing promising NLO properties for optoelectronic applications.

三唑类化合物是一种含氮杂环化合物，因其在药物化学、药物发现、农用化学品和材料科学中的应用而受到关注。在本研究中，我们合成了N-取代的2-((5-(3-溴苯基)-4-甲基-4H-1,2,4-三唑-3-基)硫基)-N-苯基丙酰胺的新型衍生物和使用密度泛函理论（DFT）进行了全面的研究。这些新颖的 1,2,4-三唑结构杂化物是通过 3-溴苯甲酸(1)的多步化学修饰合成的。最初，化合物1转化为3-溴苯甲酸甲酯(2) ，然后转化为3-溴苯甲酰肼(3) 。最后一步涉及化合物 3 的环化，产生其 1,2,4-三唑衍生物(4) 。然后将该中间体与不同的亲电子试剂偶联，形成最终衍生物(7a–7c) 。此外，还利用红外、核磁共振氢谱和紫外可见光谱等技术对这些三唑基化合物（ 7a、7b和7c ）进行了表征，以了解它们的结构和光谱特性。 DFT 研究利用 M06/6-311G(d,p) 泛函来研究几何参数、HOMO-LUMO 能量、自然键轨道分析、跃迁密度矩阵 (TDM)、态密度和非线性光学 (NLO) 特性。 FMO 分析显示化合物7c表现出最低的带隙值（4.618 eV）。值得注意的是，化合物7c表现出显着的线性极化率 (4.195 > × 10 ^–23 ) 以及第一和第二超极化率 (6.317 > × 10 ^–30 , 4.314 × 10 ^–35 )，表明其在非线性光学应用中的潜力。这些 NLO 特性意味着我们的每种化合物，尤其是7c ，在制造材料中发挥着至关重要的作用，这些材料在光电应用中表现出有前景的 NLO 特性。