Chelating Diazoarylcelluloses for Selective Chromogenic Reactions

A number of polydentate diazoarylcelluloses have been proposed in the form of reagent indicator, in which the functional diazo group is connected to the rest of the molecule through fragments of crown ether. When azo coupling of diazoaryl celluloses with amino and hydroxy aryl compounds having an azo coupling active in the molecule, a coordination cavity was formed, the denticity of which was increased due to donor atoms of the formed azo group and the adjacent ortho substituent from the azo component. This led to the formation of polydentate chelants, few differing in color, but in the presence of one or another metal ion—to the formation of their complexes, significantly differing from each other in color characteristics and electronic absorption and diffuse reflection spectra. Examples of selective chromogenic reactions of diazoarylcelluloses with 2-naphthol with the participation of gold(III) in a mixture of structurally similar substances and with 2,4-xylidine with the participation of cobalt(II) in a mixture of 6 isomeric xylidines are given.