Diethyl sulfide is primarily used as a solvent in various chemical reactions and processes due to its ability to dissolve a wide range of organic compounds. It is also employed in the synthesis of other chemicals, particularly in the production of organosulfur compounds. In the petrochemical industry, it serves as an additive to improve the efficiency of certain refining processes. Additionally, diethyl sulfide finds application in the field of organic synthesis as a reagent for introducing ethylthio groups into molecules. Its strong, distinctive odor makes it useful in odorant formulations for natural gas, helping to detect leaks. In research, it is utilized as a ligand in coordination chemistry and as a precursor in the preparation of metal sulfide nanoparticles.