Binuclear biologically active Co(II) complexes with octazamacrocycle and aliphatic dicarboxylates

Four new cationic Co(II) complexes with N,N′,N′′,N′′′-tetrakis (2-pyridylmethyl)-1,4,8,11-tetraazacyclotetradecane (tpmc) and dianion of one the aliphatic dicarboxylic acids: butanedioic acid (succinic) acid = succH2, pentanedioic (glutaric) acid = gluH2, hexanedioic acid (adipic) acid = adipH2 or decanedioic acid (sebacic) acid = sebH2 of general formula [Co2(L)(tpmc)](ClO4)2⋅xY, L2− = succ, x = 1, Y = H2O; L = glu, x = 1, Y = H2O; L = adip, x = 1.5, Y = H2O; L = seb, x = 1, Y = CH3CN were isolated. The composition and charge are proposed based on elemental analyses (C, H, N) and electrical conductivity measurements. UV–Vis and FTIR spectral data and magnetic moments were in accordance with high-spin Co(II) state. It is proposed that in all complexes Co(II) is hexa-coordinated out of cyclam ring and that both carboxylic groups from dicarboxylate bridge participate in coordination. Oxygens from one group are most likely bonded to the same Co(II) ion thus forming a four-membered ring. The in vitro antibacterial/antiproliferative activities of the complexes were in some cases enhanced compared with the simple Co(II) salt and free ligands, tested as controls.

► Synthesis of Co(II) octazamacrocycle complexes with aliphatic dicarboxylates.
► Succinic, glutaric, adipic and sebacic acids as bridged co-ligands.
► Analytical, spectral and physico-chemical characterization of Co(II) complexes.
► In vitro antibacterial and antiproliferative activity of the complexes is found.