3122-07-4Relevant academic research and scientific papers
Acetonylperoxyl Radicals, CH3COCH2O2: A Study on the γ-Radiolysis and Pulse Radiolysis of Acetone in Oxygenated Aqueous Solutions
Zegota, Henryk,Schumann, Man Nien,Schulz, Dorothea,Sonntag, Clemens von
, p. 1015 - 1022 (2007/10/02)
Hydroxyl radicals from the radiolysis of N2O/O2 (4:1)-saturated aqueous solutions of acetone (1E-3 mol dm-3) react with the solute by H-abstraction thereby forming acetonyl radicals.As shown by pulse radiolysis, the acetonyl radicals rapidly add oxygen (k = 3E9 dm3 mol-1 s-1) thereby forming acetonylperoxyl radicals which decay by second-order kinetics (2k = 8E8 dm3 mol-1 s-1).Under steady-state radiolysis conditions (0.24 Gy s-1) the products (G values in parentheses) are methylglyoxal (2.5), hydroxyacetone (0.5), formaldehyde (1.6), acids (1.7), carbon dioxide (0.5), organic (hydro)peroxides (0.4), hydrogen peroxide (2.2), and G (oxygen uptake) has been determined at 5.2.In the decay of the acetonylperoxyl radicals the major process (slightly less than one half) leads in a concerted reaction to two molecules of methylglyoxal and one molecule of hydrogen peroxide.The Russel mechanism which yields one molecule of methylglyoxal, hydroxyacetone and oxygen contributes about one fifth as does the breakdown into two molecules of formaldehyde, one molecule of oxygen and two acetyl radicals.Carbon dioxide, formaldehyde and acetic acid are among the products which result from the acetylperoxyl radicals formed upon oxygen addition to the acetyl radicals.About one tenth of the organic peroxyl radicals is converted into hydroperoxides by O2 produced as a byproduct in the water radiolysis. - Key words: Pulse Radiolysis, Acetone, Acetonylperoxyl Radical, Superoxide Radical
Abschaetzung kinetischer und thermodynamischer Daten fuer Wasserstoffabspaltungsreaktionen von niederen Olefinen
Scherzer, K.,Lohse, K.,Loeser, U.
, p. 196 - 204 (2007/10/02)
Mit Hilfe der BEBO-Methode sind fuer 500 ... 1200 K die Aktivierungsparameter der H-Uebertragungsreaktionen .R1 + HR2 --> R1H + R2.(R1: H, CH3, C2H5, n-C3H7, i-C3H7, CH3CO, CH2COCH3; R2H: Ethen, Propen, But-1-en) berchnet worden.Unter Verwendung entsprechender Daten der Rueckreaktion wurden daraus ΔRGθ, ΔRHθ und ΔRSθ bestimmt und mit den aus thermochemischen Inkrementen zugaenglichen Werten verglichen.Die Beweiskraft der guten Uebereinstimmung beider Datensaetze fuer die Anwendbarkeit des BEBO-Verfahrens auf H-Abstraktionen von Olefinen wird diskutiert.Ausserdem wird gezeigt, dass bei der Pyrolyse von Olefinen die H-Abstraktion aus der Vinylgruppe bis ueber 1500 K gegenueber der aus den Alkylgruppen zu vernachlaessigen ist.
