Synthesis, structural characterization and antiproliferative and toxic bio-activities of copper(II) and nickel(II) citronellal N4-ethylmorpholine thiosemicarbazonates

This paper reports the syntheses and characterization of ethylmorpholine substituted citronellal thiosemicarbazone copper(II) and nickel(II) metal complexes. The compounds were characterized through elemental analyses and spectroscopic (IR, UV–Vis, NMR, MS) methods. The X-ray analysis of the two complexes shows that both Ni and Cu derivatives present a square planar coordination, where the coordinating homologous donor atoms bind in trans to each other. The compounds were tested for their biological activity after determination of their octanol–saline partition coefficients, followed by their radical scavenging properties. Eventually the complexes were tested for their proliferation inhibition on human histiocytic lymphoma U937 cell line. The GI50 values resulted to be 2.3 μM for the copper derivative and 12.3 μM for the nickel derivative.