Synthesis and characterization of new Cu(II) complexes derived from benzilic and mandelic hydrazones

Two new sets of Cu(II) complexes with newly synthesised benzilic and mandelic hydrazone derivatives were prepared in the mole ratios 1:1 and 1:2 (Cu:L). The structure of the complexes was identified on the basis of the data obtained from elemental and thermal analyses as well as IR, UV-visible, ESR spectra, and X-ray diffraction. The results indicate that the ligands are tightly bound to the metal ion through the phenolic OH oxygen, the azomethine nitrogen, and the enolic OH oxygen in case of the 1:1 complexes while for the 1:2 complexes the enolic OH group did not participate in bonding. The complexes have elongated octahedral as well as square-planar symmetries. [GRAPHICS]