The Chromium(III) Complexes with Ammoniatriacetic Acid. II. The Mixed-ligand Complexes

Abstract

Abstract The following chromium(III) complexes containing ammoniatriacetic acid (ATA) and other reagents as “mixed-ligands” were newly prepared: NH4[Cr(ata) (acac)]·H2O (brown black)(I), [Cr(ata)(o-phen)]·4H2O (brown) (II), [Cr(ata)(dipy)] (red brown)(III), (NH4)2[Cr(ata)·(NCS)2]·H2O (purple black)(IV, and K2[Cr(ata)(ox)]·2H2O(purple)(V), where ata, acac, o-phen, dipy and ox are the abbreviations of the ammoniatriacetate ion, acetylacetone, o-phenanthroline, α,α-dipyridyl, and the oxalate ion respectively. On the basis of the chemical analyses, the thermal analyses, and the measurements of the electronic absorption spectra, it may be considered that ATA was coordinated as a tetradentate ligand in all these complexes obtained. Further information on the conductivity in an aqueous solution suggested that the IV and V complexes are aquated instantly to form the complex ion as [Cr(OH)(ata)(H2O)2]−. The values of the effective magnetic moments for these complexes were 3.7–3.9 B. M., nearly equal to the spin-only values of tervalent chromium.