Geometry of new iron(III) and copper(II) azo-nitroso-complexes

Summary The synthesis and characterization of new iron(III) and copper(II) complexes of substituted phenylazo-2,4-dinitrosoresorcinol complexes are described. The iron complexes are of octahedral geometry (high-spin and low-spin states). The electronic transitions and the ligand field parameters (B, and ) are assigned and calculated. Two series of copper complexes were prepared, mononuclear and dinuclear, with distorted tetrahedral and square planar configurations, respectively. The adducts of the complexes with pyridine have square pyramidal structures. Complex formation takes placevia the azo-group and the phenolic oxygen atom in most cases.