Electron Paramagnetic Resonance Detection of Singlet Oxygen: Opportunities and Pitfalls of Sterically Hindered Amine Trapping Agents.

ABSTRACT: Singlet oxygen (¹O₂), a nonradical reactive oxygen species, has shown great potential for driving redox reactions. Electron paramagnetic resonance (EPR) spectroscopy has become a widely utilized tool for identifying the adducts formed by ¹O₂ with sterically hindered amines and indirectly determining the concentrations of ¹O₂. However, the characteristic 1:1:1 triplet EPR signal of ¹O₂ adduct can arise from other molecules and impurities. In this work, we demonstrate the presence of N-oxyl impurities in commercial 2,2,6,6-tetramethylpiperidine (TEMP) derivatives can lead to overestimation of ¹O₂ in redox systems. Additionally, the relatively low water solubility of TEMP may cause un

SUBMITTER: Lau CY 

PROVIDER: S-EPMC12807558 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature