Structural relevance of mixed-donor macrocyclic Co(II) complexes to chromotropism

Herein are described the synthesis and characterization of a macrocyclic series of Schiff base complexes with CoX2(where X = Cl, NO3, SCN). All of the compounds are characterized by elemental analyses, conductometric measurements, infrared absorption and reflectance spectra. The effect of macrocyclic ring-size and counter anions on the chromotropism of the complexes, in the solid state and their solution in DMSO, have also been investigated. It is found that similar electronic spectra and conductance are maintained no matter what the size of the macrocycles is. On account of these experiments, it has been concluded that variation in the counter anions is responsible for the observed chromotropism.