tert-Nitrosobutane dimer is primarily utilized in organic synthesis as a nitrosating agent, facilitating the introduction of nitroso groups into various organic compounds. It is particularly valuable in the preparation of nitroso derivatives, which are intermediates in the synthesis of pharmaceuticals, dyes, and other fine chemicals. Additionally, it finds application in polymer chemistry, where it can act as a cross-linking agent or initiator in the polymerization process, enhancing the properties of the resulting polymers. Its role in research and development is also notable, as it aids in the study of reaction mechanisms involving nitroso compounds.