54513-88-1Relevant academic research and scientific papers
Nucleophilic activation of hydrogen peroxide. On the formation and the reactivity of 1H-1,2,4-triazoleperoxycarboxylic acid and O-p-nitrophenylmonoperoxycarbonic acid
Bender, Carsten,Brauer, Hans-Dieter
, p. 2579 - 2587 (1999)
Measurements of the infrared phosphorescence of singlet molecular oxygen (1O2) at 1270 nm have been employed to demonstrate the formation of 1O2 in the system N,N′-carbonyldi-1,2,4-triazole (CDT)-hydrogen peroxide and in the system 1H-1,2,4-triazolecarboxylic acid p-nitrophenyl ester (TCNP)-hydrogen peroxide in tetrahydrofuran. At hydrogen peroxide concentrations of [H2O2] ≥ 2 [CDT] or ≥ 2 [TCNP] one molecule of 1O2 is generated per molecule of CDT and TCNP, respectively. In both systems a very reactive peroxy-intermediate is formed. In the system CDT-H2O2 the 1H-1,2,4-triazoleperoxycarboxylic acid (1) is generated, in TCNP-H2O2 the p-nitrophenylmonoperoxy-carbonic acid (4). For the epoxidation of cyclohexene in THF by 1 a rate constant k15 ≈3 x 100 dm3 mol-1 s-1 can be estimated. For 4 the corresponding rate constant was found to be k20 ≈ 6 x 10-2 dm3 mol-1 s-1. The Arrhenius parameters of the formation of 1 and 4, respectively, and in addition of their consecutive reactions with hydrogen peroxide were determined. The results are consistent with the assumption that the nucleophilic displacements by hydrogen peroxide at the carbonyl carbon atom are addition-elimination processes, which take the form of a BAC2-mechanism.
