Complexes of Co(II), Ni(II), and Zn(II) with pyrazolone ligands

Abstract

Complexes of Co(II), Ni(II), and Zn(II) with 4-aminoantipyrine and 4-dimethylaminoantipyrine have been prepared and characterized. These contain chloride, bromide, thiocyanate, nitrate, and perchlorate anions. Magnetic, conductivity, and electronic spectral data show that all of the Ni(II) and Co(II) complexes have high spin configurations and octahedral geometries, with coordinated halide, thiocyanate, and probably nitrate anions in the respective examples. Infrared analysis indicates that all of the complexes containing Cl−, NCS−, and NO3− anions involve chelated 4-aminoantipyrine, whereas the bromide complexes are only bonded to the organic ligands through nitrogen.