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8321417 
Journal Article 
The mechanism of the etard reaction 
Necsoiu, I; Balaban, AT; Pascaru, I; Sliam, E; Elian, M; Nenitzescu, CD 
1963 
1 
Tetrahedron
ISSN: 0040-4020 
19 
7 
1133-1142 
English 
Electron spin resonance measurements show that one of the two chromium atoms in Etard complexes is diamagnetic, hence sexivalent, whilst the other is paramagnetic, therefore the second chromium atom has a slower valency state and is probably quadrivalent. By decomposing the Etard complexes of diphenylmethane and of n-propylbenzene with sulphur dioxide containing solutions, the corresponding alcohols are obtained in appreciable amounts, along with the known ketones. Primary and secondary alcohols such as benzyl alcohol and benzhydrol are smoothly oxidized in aqueous suspension by one mole of chromyl chloride. Therefore, alcohols are probably the primary products in the hydrolysis of Etard complexes. It is admitted that the first step in oxidations by chromic acid or by chromyl chloride consists in the transfer of a hydride ion from substrate to oxidant, converting one Cr(VI) atom to Cr(IV), which remains bound to a second Cr(VI) atom. © 1963.