: In this work, the important features, electrochemical, optical and thermal stability as antioxidant, of four new donor-acceptor–π–acceptor-donor architecture, antioxidant dyes based on thiadiazole were studied. The four dyes carry aryl amino groups as the donors, two 1, 3, 4-thiadiazole moieties as the acceptors and azo and phenyl groups as π spacers. The effect of different aryl amino substituents as the donor group on optimization molecules, geometric, optical properties and electronic properties were studied and discussed. These azo dyes were synthesized by diazotization of 1, 4-bis (2-amino-1,3,4 -thiadiazole)benzene and coupling with different aromatic compounds, and their structures were recognized by UV spectroscopy and 1H NMR, FTIR, and elemental analysis. Interestingly, these compounds proved to be as important for lubricants as antioxidants. Outcome of run Density functional theory DFT-based quantum calculations on these dyes so allow comprehensive information in correlation with their cell high performance. Electron donor substrate based on organic solar cells shows power conversion efficiency (PCE) of 5.3 % with 0.93 as high open-circuit voltage by simple solution spin-coating manufacturing procedure. The efficiency of the prepared azo day passes to inhibition base oil from oxidation.