Trimethylphosphine oxide is primarily used as a ligand in coordination chemistry, where it stabilizes metal complexes due to its strong electron-donating properties. It is also employed in organic synthesis as a reagent or catalyst in various reactions, such as the reduction of carbonyl compounds or the formation of phosphine-based intermediates. In material science, it serves as a precursor for the synthesis of phosphorus-containing polymers and coatings, which can enhance thermal stability and flame retardancy. Additionally, it finds applications in nuclear magnetic resonance (NMR) spectroscopy as a reference compound for studying phosphorus-containing molecules. Its role in catalysis and material modification makes it valuable in both industrial and research settings.