Ce(III), Th(IV) and U(VI) chelates of alizarin viridine, alizarin heliotrope and alizarin maroon

The complexes of 7,8‐dihydroxy‐1,4‐di(2′‐sulpho‐4′‐methylanilano)anthraquinone (alizarin viridine); 1,4‐dihydroxy‐2(2′‐sulpho‐4′‐methylanilino)anthraquinone (alizarin heliotrope) and 3‐amino‐1,2‐dihydroxyanthraquinone (alizarin maroon) with Ce(III), Th(IV) and U(VI) have been investigated using spectrophotometric and conductometric methods. The study revealed the formation of complexes having the metal: ligand ratios 1:1 and 1:2. The values of log β* for the different complexes are determined. The structure of the ligands in the solid chelates were studied by i.r. spectrophotometry which showed that chelate formation takes place through the CO and neighbouring OH group and leads to proton displacement.