Metallionen und H2O2. IV. Über Struktur und Aktivität der den H2O2-Zerfall katalysierenden Cu2+-Komplexe. II. Einfluss der Zahl der freien Koordinationsstellen

The Cu²⁺ chelates of the bidentate ligands 2,2′-bipyridine (I; 2]), N, N′-diglycyl-1,5-diaminopentane (VI), ethylenediamine (II; 2]), glycine (V) and pyrophosphate (III; 2]) are found–parallel to the spectrochemical series–to be more active in catalysis of H₂O₂ decomposition than the chelates of the terdentate ligands–antiparallel to the spectrochemical series–iminodiacetic acid (IX), glycylglycine (VIII), 2, 2′-diaminodiethylamine (VII) and 2, 2′, 2″-terpyridine (IV; 2]), the activity decreasing in the given series. If all four coordination positions of Cu²⁺ are engaged (e.g. complex with N, N′-di-(2-aminoethyl)-ethylenediamine (X)) the complex is inactive. The catalytic activity of the Cu²⁺-chelates is parallelled by the tendency to form ternary peroxo complexes.