The Structure of Cobalt(II) Acetate and Cobalt(III) Acetate in Acetic Acid Solution

Abstract

Optical and ion migration experiments were carried out with acetic acid solutions of Co" and Co"' acetate. The results indicate a mononuclear structure with six ligands. The largest amount of these complexes is uncharged.

Byproduct identification in the terephthalic acid production process and possible mechanisms of their formation

“…It has been shown that cobalt(M) decomposes the acetic acid yielding methyl radical and carbon dioxide (Hendriks, 1979). The methyl radical formation in the p-xylene oxidation process is evidenced by the presence of CH4 in the off-gases and of methanol and methyl acetate in the mother liquor.…”

The Role of Iodanyl Radicals as Critical Chain Carriers in Aerobic Hypervalent Iodine Chemistry

“…In addition to functioning as an autoxidation initiator, Co(III) species can oxidize peracids to generate peroxy radicals (i.e., oxidation of D to generate C), and Co(II) species are readily oxidized to Co(III) by peracids (i.e., D). 82 One might also envision direct oxidation of PhI by Co(III). 82,83 The following lines of experimental evidence suggest that Co-based additives are not intimately involved in the oxidation of PhI.…”

“…82 One might also envision direct oxidation of PhI by Co(III). 82,83 The following lines of experimental evidence suggest that Co-based additives are not intimately involved in the oxidation of PhI. (1) Co-based promoters are not necessary for aldehyde-promoted aerobic oxidation of aryl iodide.…”

“…Removal of these additives from aerobic oxidation reactions results in variable initiation time, but a high yield of PhI(OAc) 2 can still be obtained. 58 (2) Exposure of PhI to an AcOH solution of Co(OAc) 3 , 82 which is the product of aerobic oxidation of Co(II) in AcOH, did not result in the observation of any PhI(OAc) 2 (Figure S11). (3) Comparison of the concentration-versus-time plots for aerobic oxidation with and without Co(II) (1 mol % CoCl 2 $6H 2 O; Figure S12) revealed that although the length of time that is required for initiation depends intimately on the presence of Co(II), once oxidation commences, the presence of Co initiators does not affect the kinetics of oxidation.…”

Methyl acetate: by-product in the terephthalic acid production process. Mechanisms and rates of formation and decomposition in oxidation

“…The latter is oxidized to methyl acetate according to the following equation, which summarizes both stages (Hendriks et al, 1979): formation of methyl acetate, and their kinetics can be modified by varying the reaction conditions, the methyl acetate formation was also expected to depend on given specific parameters of the oxidation process. In fact, during our investigation of the p-xylene oxidation reaction, we could verify that the methyl acetate formation is namely affected by variations in the following parameters: water concentration in the reaction medium, oxidation temperature, p-xylene oxidation rate, and catalytic system composition.…”