7354-48-5Relevant academic research and scientific papers
A continuous visible light spectrophotometric approach to accurately determine the reactivity of radical-trapping antioxidants
Haidasz, Evan A.,Van Kessel, Antonius T. M.,Pratt, Derek A.
, p. 737 - 744 (2016)
Inhibited autoxidations-monitored either by O2 consumption or hydroperoxide formation-are the most reliable way to obtain kinetic and stoichiometric information on the activity of radical-trapping antioxidants (RTAs). While many comparatively simple "antioxidant assays" (e.g., the DPPH assay) have supplanted these in popularity, they are generally very poor substitutes since they often do not employ peroxyl radicals as the oxidant and do not account for both the kinetics and stoichiometry of the radical-trapping reaction(s). In an effort to make inhibited autoxidations as simple as the most popular "antioxidant assays", we have developed a spectrophotometric approach for monitoring reaction progress in inhibited autoxidations. The approach employs easily prepared 1-phenylbutadiene-conjugated or styrene-conjugated BODIPY chromophores (PBD-BODIPY or STY-BODIPY, respectively) as signal carriers that co-autoxidize along with a hydrocarbon substrate. We show that inhibition rate constants (kinh) are accurately determined for a range of phenolic and diarylamine RTAs using this approach and that mechanistic experiments, such as kinetic isotope effects and kinetic solvent effects, are equally easily carried out. Moreover, synergistic interactions between RTAs, as well as the unconventional activity of diarylamine RTAs, are captured using this methodology. Lastly, we show that the approach can be employed for monitoring reactions in aqueous solution.
High-resolution single-turnover mapping reveals intraparticle diffusion limitation in Ti-MCM-41-Catalyzed epoxidation
De Cremer, Gert,Roeffaers, Maarten B. J.,Bartholomeeusen, Evelyne,Lin, Kaifeng,Dedecker, Peter,Pescarmona, Paolo P.,Jacobs, Pierre A.,De Vos, Dirk E.,Hofkens, Johan,Sels, Bert F.
, p. 908 - 911 (2010)
(Figure Presented) Shedding light on catalysis: For the first time, transport phenomena and their influence on catalysis are directly observed for individual catalytic particles by single-turnover mapping using highresolution fluorescence microscopy. The Thiele modulus could be measured with just one experiment, proving the existence of diffusional limitations for the Ti-MCM-41 catalyzed epoxidation of a fluorescent reporter molecule (see picture; TBH P = tert-butylhydroperoxide).
