Nitrosonium hexafluoroantimonate is primarily used as a strong nitrosating agent in organic synthesis. It facilitates the introduction of nitroso groups into various organic compounds, which is crucial in the production of dyes, pharmaceuticals, and agrochemicals. Additionally, it serves as a powerful oxidant in certain chemical reactions, enabling the transformation of substrates that are otherwise difficult to oxidize. Its application extends to the preparation of specialty chemicals and intermediates, where its reactivity is leveraged to achieve specific molecular modifications. In research, it is valued for its ability to generate nitrosonium ions, which are essential in studying reaction mechanisms and developing new synthetic pathways.