The aminoxyl radical (> NO) BTNO (benzotriazole-N-oxyl) has been generated by the oxidation of 1-hydroxybenzotriazole (HBT;> N-OH) with a CeIV salt in MeCN. BTNO presents a broad absorption band with λmax 474 nm and ε 1840 M-1 cm-1, and spontaneously decays with a first-order rate constant of 6.3× 10-3 s-1 in MeCN at 25° C. Characterization of BTNO radical by EPR, laser flash photolysis, and cyclic voltammetry is provided. The ...