Generation and Spectroscopic Identification of the Thiuram Radical (CH₃)₂NCS₂

We report the first preparation, matrix-isolation, and IR and UV/vis spectroscopic characterization of the thiuram radical that is a highly important species for many industrial processes. The thiuram radical was prepared by thermal dissociation of tetramethylthiuram disulfide and was identified by matching its spectroscopic data with density functional theory [UB3LYP/6-311++G­(3df,3pd)] computations. The title compound proved to be highly photolabile, and irradiation with light at λ = 623 nm affords a hitherto unknown carbamodithioic acid, N-(methyl)-N-methyl radical, as characterized by IR and UV/vis spectroscopy in low-temperature matrices.