Tricyclische CuII- und NiII-Chelate aus 2,2-Bis-(2-hydroxyarylazo)-biphenyl bzw. -diphenylsulfid

Tricyclic Cu^II and Ni^II chelates are produced from some 2,2′-bis-(2-hydroxyaryl-azo)-biphenyls and -diphenyl sulphides. From their electron spectra it is concluded that in the Ni complexes of the azo-biphenyl dyestuffs the central atom is coordinated in a different way (probably planar) from that in the corresponding Cu complexes. On the other hand, the valences of both metals in the azo-diphenyl sulphide complexes seem to have the same steric arrangement. This arrangement is probably the same as that of the Cu^II ion in the azobiphenyl dyestuffs, which could be tetrahedral.