Used as a deuterated solvent in nuclear magnetic resonance (NMR) spectroscopy, enabling clear analysis of proton signals by eliminating interference from solvent protons. Its deuterium atoms provide a lock signal for the NMR instrument, improving spectral stability and accuracy. Commonly employed in structural elucidation of organic compounds, pharmaceuticals, and biomolecules where high-resolution spectra are required. Also serves as a solvent in kinetic isotope effect studies and in deuteration reactions where a deuterated aromatic environment is needed.