Used primarily as a deuterated solvent and internal standard in nuclear magnetic resonance (NMR) spectroscopy. Its fully deuterated structure makes it ideal for studying reaction mechanisms and molecular structures in organic and organometallic chemistry. It is also employed in kinetic isotope effect studies, where the replacement of hydrogen with deuterium helps elucidate reaction pathways. Due to its stability and distinct spectral properties, it supports accurate calibration and signal assignment in high-resolution NMR analyses. Additionally, it serves as a labeled reagent in the synthesis of deuterium-enriched compounds for pharmaceutical and metabolic research.