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Summary.:  In this study, the electrochemical properties of novel porphyrazines with eight crown ether substituents appending on the periphery through flexible chains were investigated by using cyclic voltammetry and controlled potential coulometry. Cyclic voltammetry measurements showed that the metal free porphyrazine gave all of the six possible redox reactions of common porphyrazine derivatives. Cobalt porphyrazine exhibited a metal-based reduction and a metal-based oxidation processes followed by two ligand-based reduction and two oxidation processes. I p vs. ν1/2 plots of redox processes of the two compounds indicated the diffusional mass transfer mechanism of the complexes. Copper porphyrazine gave an oxidation process having adsorption properties and three reduction reactions. The variations of peak current ratios of electrochemical reactions for all three complexes with scan rate showed that electron transfer processes of complexes were followed by reversible or irreversible chemical reactions. Aggregation and sandwich adduct formation properties of complexes were determined by CV measurements. Peak potentials of redox processes for all complexes were shifted towards positive potentials by addition of alkali metal cations. Addition of K+ formed sandwich type adducts with 15-crown-macrocycles diminishing aggregation of planar molecules by intramolecular rather than intermolecular complexation.

4′-(ω-Salicylaldiminoacetyl)benzo(15-crown-5) (LH) has been synthesized from 4′-(ω-aminoacetyl)benzo(15-crown-5) and salicylaldehyde. Complexes of this Schiffbase with copper(II), nickel(II), cobalt(II), and uranyl(VI) have been prepared from the corresponding metal acetates and chlorides. Insertion of sodium ions into the crown ether-moiety has been accomplished by refluxing LH with sodium nitrate in ethanol. The complexation of this ligand with Cu(II), Ni(II), Co(II), and U(VI)O2was investigated by potentiometric titration; the results indicate that all of them afford products with a metal-ligand ratio of 1:2. The order of formation constants of the mononuclear complexes is Cu(II)>Co(II)>U(VI)O2>Ni(II). 4′-(ω-Salicylaldiminoazetyl)benzo(15-crown-5) (LH) wurde ausgehend von 4′-(ω-Aminoacetyl)-benzo(15-crown-5) und Salicylaldehyd synthesiert. Komplexe dieser Schiffschen Base mit Kupfer(II), Nickel(II), Kobalt(II) und Uranyl(VI) wurden aus den entsprechenden Metallacetaten hergestellt. Einfügung von Natriumionen in den Kronenetherteil der Moleküle wurde durch Kochen mit Natriumnitrat in Ethanol unter Rückfluβ erreicht. Die Komplexbildung mit Ni(II), Cu(II), Co(II) und U(VI)O2wurde durch potentiometrische Titration untersucht; alle Metalle ergeben dieselben Komplexe mit einem Metall-Ligand-Verhältnis von 1:2. Die Reihenfolge der Bildungskonstanten der einkernigen Komplexe lautet Cu(II)>Co(II)>U(VI)O2>Ni(II).