The oxidation of d-myo-inositol (Myo) by CrVI yields the inosose and Cr3+ as final products when an excess of cyclitol over CrVI is used. The redox reaction takes place through the combination of CrVI → CrIV → CrII and CrVI → CrIV → CrIII pathways. Intermediacy of CrIV was evidenced by the detection of CrO22 +, formed by reaction of CrII with O2. The EPR spectra show that five- and six-coordinated oxo-CrV intermediates are formed, with the cyclitol acting as bidentate ligand. Penta-coordinated oxo-CrV species are present at any [H+], whereas hexa-coordinated ones are only observed at pH < 1, where rapidly decompose to the redox products. At higher pH, where hexa-coordinated oxo-CrV species are not observed, oxo-CrV bischelates are stable enough to remain long time in solution.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry