An extensive research on 6-benzylaminopurine derivatives proceeds continually for several decades because of their potential use as plant growth hormones (cytokinins) and cyclin-dependent kinase inhibitors. A series of octahedral copper(II) complexes bearing 6-(4-fluorobenzylamino)purine (L1), 6-(3-fluorobenzylamino)purine (L2), 6-(2-fluorobenzylamino)purine (L3) and 6-(3-chlorobenzylamino)purine (L4) have been prepared and characterized by elemental analysis, IR, UV/VIS, and mass spectroscopy, magnetic susceptibility and conductivity measurements, and by thermal (TG/DTA/DSC) analysis. Based on results following from the used techniques, the composition and stereochemistry of the prepared complexes can be described as cis,trans-[Cu(L)₂(H₂O)₂(phen)]×n(MeOH), where L = L1, L2, L3, or L4; phen = 1,10-phenanthroline; n = 0 or 1. In vitro cytotoxicity and SOD-like activity, and in vivo antidiabetic activity as well as the number broadening of the complexes will be our objectives in the nearest studies.