Abstract
The coordination of the benzothiazole derivatives to divalent metal ions in solutions were examined by their absorption and resonance Raman spectra, and the comparison of the reactivities of the structurally related compounds with metal ions. In the solid state it was also investigated by the infrared spectrum and the magnetic susceptibility. Both in the solid state and in solutions, the benzothiazole derivatives behave as terdentate chelating agents with divalent metal ions and coordinate to the metal ions through the phenolic OH and the nitrogen atoms of the thiazole ring and the azo or azomethine group. The copper chelate has a plane structure in the molar ratio of 1 : 1 ligand-to-metal and an octahedron structure in 2 : 1, similarly to the nickel and the zinc chelates. The azohydrazone tautomerism of the benzothiazolylazo derivatives was also discussed.
