Synthesis, characterization and biological activity of two nickel(II) complexes with 6-(2-chlorobenzylamino)purine

Compounds of composition [Ni(L)(H2O)(2)Cl] and [Ni(L)(H2O)(NO3)] . EtOH [HL = 6-(2-chlorobenzylamino)purine] have been synthesized and characterized b y elemental analyses, i.r. and electronic spectra, magnetic measurements an d mass spectroscopy as tetrahedral nickel(II) complexes. The geometry of bo th complexes has been optimized using molecular mechanics modelling. Althou gh the monoanionic ligand L is potentially bidentate, we assume that the co ordination to nickel is via the N-9 atom only. Cytokinin and anti-cancer ac tivities of the complexes were also tested in an Amaranthus cytokinin bioas say and in an in vitro MTT-based cytotoxicity assay, respectively. In human T-lymphoblastic leukemia cell line CCRF-CEM both complexes showed potent c ytotoxic activity.