3,3',5,5'-Tetrakis(tert-butyl)-[1,1'-biphenyl]-2,2'-diol is a sterically hindered biphenol derivative. It is a white to off-white crystalline powder with a molecular formula of C28H42O2. The molecule features a central biphenyl core with two phenolic hydroxyl groups in the ortho positions, each flanked by bulky tert-butyl groups at the 3 and 5 positions. This structure imparts significant steric hindrance and influences its electronic properties. This compound is primarily utilized as a key monomer or precursor in the synthesis of advanced organic electronic materials. Its main application lies in the field of organic light-emitting diodes (OLEDs), where it serves as a building block for host materials, particularly in phosphorescent OLED (PHOLED) devices. The bulky tert-butyl groups help to prevent molecular aggregation and excimer formation, which is crucial for achieving high efficiency and color purity in OLED displays and lighting. Additionally, due to its hindered phenolic structure, it can act as an antioxidant or stabilizer in polymer systems. Its well-defined structure also makes it a valuable ligand in coordination chemistry and catalysis research, where it can be used to construct sterically demanding metal complexes.