Kinetics and mechanism of chromium(III)-catalysed oxidation of ethane-1,2-diol and propane-1,2-diol by cerium(IV) in aqueous sulfuric acid media
| Main Authors: | Asim K. Das, Sudhin K. Mondal, Dalia Kar, Goutam K. Bhuin, Aparna Roy |
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| Format: | Article Journal |
| Bahasa: | eng |
| Terbitan: |
, 2000
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| Subjects: | |
| Online Access: |
https://zenodo.org/record/5867155 |
Daftar Isi:
- Department of Chemistry, Visva-Bharati, Santiniketan-731 235, India Manuscript received 5 August 1999. accepted 31 December 1999 The kinetics and mechanism of chromium(lll)-catalysed oxidation of the title diols by cerium(IV) in aqueous sulfuric acid media to their corresponding aldehydes through the C-C bond cleavage (i.e. glycol splitting) under the conditions, [dioi]T >> [CeIV]T >> [Cr]T at different temperatures (35-50o) have been studied. In 1.0 mol dm-3 sulfuric acid media, the experimentally observed rate law conforms to -d In [CeIV]dt = kobs = a[dioi]T[Cr]T/{b + c[Cr]T} where, [diol]T and [Cr]T give the total concentrations of the substrate and catalyst, respectively; a, b and c are constants at a particular temperature and fixed [H2SO4]. The process has been found acid-catalysed. From the hydrogen sulfate dependence, Ce(SO4)2 has been identified as the kinetically active species. The proposed mechanism involves the formation of an intermediate involving the oxidant, catalyst and substrate, and a CrIII/CrIV catalytic cycle has been suggested to operate.