PLATINBLAU

Platinblau, the anomalously blue platinum amide complex previously thought to have the composition PtII(CH3CONH)2H2O, has been shown by crystallographic, analytical, infrared, and nmr studies to be PtIV(CH3-CONH)2(OH)3, the corresponding blue dichloride also having been prepared. A related divalent platinum complex, PtII[(CH3)3CCONH2]2Cl2 (I), contains trimethylacetamide in its iminol form, RC(OH)=NH, with coordination of the square-planar Pt by the =NH group. In a second compound of the formula PtIV[(CH3)3CCONH]2-Cl2 (II), one of the amide ligands is present as an amide anion, -C(=O)NH-, and the other as an iminol anion, -C(OH)=N-. Yellow II is readily converted into its blue tautomer (III), which is the trimethylacetamide analog of the original Platinblau, and contains both amide groups as amide anions. The crystallographic study was performed on a crystal of I doped with 20% of II and 10% of III. © 1969, American Chemical Society. All rights reserved.