Abstract: The present invention relates to chromotropic nitrone spin trapping agents, methods of making these agents, compositions comprising same, and methods of their use. In particular, azulenyl nitrones of the present invention are effective agents for trapping free radical species and find use as efficient antioxidants in physicochemical and biological systems. Accordingly, the invention also relates to spin adducts formed from the combination of azulenyl nitrones with free radicals. The compounds of the present invention are readily prepared from available starting materials and find further use in assays and in a number of diagnostic, prophylactic and therapeutic applications, including but not limited to the alleviation, modulation and inhibition of the negative effects of carbon-centered or oxygen-centered radical species and other products of oxidation. Moreover, the combination adducts may be colorimetrically detected and, optionally, isolated and characterized to obtain valuable information (e.g.