Decomposition of tert-butyl hydroperoxide into tert-butyl alcohol and O2 catalyzed by birnessite-type manganese oxides: Kinetics and activity

2014 ◽  
Vol 49 ◽  
pp. 6-9 ◽  
Author(s):  
Lin Qi ◽  
Xingyi Qi ◽  
Lili Wang ◽  
Lili Feng ◽  
Shupei Lu
Author(s):  
G. Vijayalakshmmi ◽  
M. Adinarayanna ◽  
P. Jayaprrakash Rao

The rates of oxidation of adenosine and α-tocopherol by tert-butoxyl radicals (t-BuO•) were studied spectrophotometrically. Radicals (t-BuO•) were generated by the photolysis of tert-butyl hydroperoxide (t-BuOOH) in presence of tert-butyl alcohol to scavenge •OH radicals. The rates and the quantum yields () of oxidation of α-tocopherol by t-BuO• radicals were determined in the absence and presence of varying concentrations of adenosine. An increase in the concentration of adenosine was found to decrease the rate of oxidation of α-tocopherol, suggesting that adenosine and α-tocopherol competed for t-BuO• radicals. From competition kinetics, the rate constant of α-tocopherol reaction with t-BuO• was calculated to be 7.29 x 108 dm3 mol-1 s-1. The quantum yields expt and cal values suggested that α-tocopherol not only protected adenosine from t-BuO• radicals, but also repaired adenosine radicals, formed by the reaction of adenosine with t-BuO• radicals.


2020 ◽  
Vol 3 (2) ◽  
pp. 7-10
Author(s):  
Z. М. Коmarenska ◽  
◽  
М. V. Nykypanchuk ◽  
О. І. Маkota ◽  
L. P. Оliynyk ◽  
...  

A study of the process of activation of molybdenumboride catalyst in the reaction of epoxidation of octene-1 with tert-butyl hydroperoxide and the effect on this process of the initial concentration of octene-1, tert-butyl hydroperoxide and the amount of catalyst in the reaction mixture. As well as reaction products (tert-butyl alcohol and epoxy). It is shown that over time a new amorphous phase is formed on the surface of Mo2B, which actually catalyzes the epoxidation reaction of octene-1 with tert-butyl hydroperoxide. The formation of this phase is the reason for the acceleration of the rate of consumption of hydroperoxide and the selectivity of the formation of epoxide over time.


2012 ◽  
Vol 16 (05n06) ◽  
pp. 423-433 ◽  
Author(s):  
Timothy D. Lash

Vogel discovered a large number of bridged annulene structures, including constitutional porphyrin isomers, heteroporphyrinoid species such as the tetraoxaporphyrin dication, corrole isomers and novel expanded porphyrinoid systems. In this review, the impact of Vogel's work on the author's research program is discussed. Carbaporphyrinoid systems with one or two carbocyclic rings replacing the usual pyrrole subunits have been synthesized and their diatropic characteristics can be related to the presence of 18π electron delocalization pathways within these macrocycles. The preparation of a dideazaporphyrin also provides strong support for the concept, espoused by Vogel, that porphyrins are examples of bridged annulenes. Ring contractions of azuliporphyrins to benzocarbaporphyrins with tert-butyl hydroperoxide in the presence of base have been proposed to involve a Cope rearrangement where a cycloheptatriene unit rearranges to give a norcaradiene-fused carbaporphyrinoid, followed elimination of tert-butyl alcohol, and Vogel's investigations into these types of valence tautomerization processes provides insights into these unusual transformations. In addition, a new class of porphyrin isomers has been synthesized and these porphyrin analogs extend the observations previously made for N-confused porphyrins and Vogel's constitutional isomers.


1993 ◽  
Vol 58 (5) ◽  
pp. 1001-1006 ◽  
Author(s):  
Oľga Vollárová ◽  
Ján Benko

The kinetics of oxidation of [Co(en)2SCH2COO]+ with S2O82- was studied in water-methanol and water-tert-butyl alcohol mixtures. Changes in the reaction activation parameters ∆H≠ and ∆S≠ with varying concentration of the co-solvent depend on the kind of the latter, which points to a significant role of salvation effects. The solvation effect on the reaction is discussed based on a comparison of the transfer functions ∆Ht0, ∆St0 and ∆Gt0 for the initial and transition states with the changes in the activation parameters accompanying changes in the CO-solvent concentration. The transfer enthalpies of the reactant were obtained from calorimetric measurements.


2012 ◽  
Vol 14 (13) ◽  
pp. 3384-3387 ◽  
Author(s):  
Erbo Shi ◽  
Ying Shao ◽  
Shulin Chen ◽  
Huayou Hu ◽  
Zhaojun Liu ◽  
...  

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