Methyl orange, cleavage

The photoelectrochemical reduction of the N = N double bond of the diaryl azo dye methyl orange can be similarly sensitized by colloidal titanium dioxide les, isoj The reaction was sensitive to pH and the identity of the organic redox reaction could be shifted by conducting the photoreaction in the presence of surfactants. Cationic surfactants increased the efficiency of oxidative cleavage by inhibiting charge recombination. Polyvinyl alcohol instead favored reduction. The ambident photoactivity of methyl orange thus makes it an attractive probe for activity of irradiated semiconductor suspensions. 

Cleavage adjacent to nitrogen was also observed in the photoelectrochemical demethylation of methyl orange [127], Photocatalytic cleavage of an A -methyl group was competitive with C-N cleavage adjacent to the azo linkage. 

As an example of identification, the cleavage of methyl orange and the identification of components will be described. 

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