Triethylphosphine oxide is widely used as a ligand in coordination chemistry, where it stabilizes metal complexes in catalytic processes. It plays a significant role in organic synthesis, particularly in the preparation of organophosphorus compounds. Additionally, it is employed as a solvent or additive in various chemical reactions due to its ability to enhance reaction efficiency. In material science, it is utilized in the development of advanced polymers and coatings, contributing to improved material properties. Its applications also extend to the pharmaceutical industry, where it aids in the synthesis of active pharmaceutical ingredients.