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New carboxylate complexes of the tetraazamacrocyclic ligand N,N',N'',N'''-tetrakis(2-pyridilmethyl)-1,4,8,11-tetraazacyclotetradecane (tpmc) with Ni(II) and Zn(II) as central ions were prepared. In mixed-ligand complexes (endo,endo)-bicyclo[2.2.1]hept-5-ene-2,3-dicarboxylate dianion (C 9 H 8 O 4 2-) is also coordinated to metal ions. The complexes were characterized by elemental analysis (C, H, N), FTIR and UV-Vis spectroscopy, molar conductivity determination and magnetic susceptibility measurement at room temperature. The analytical data of the complexes show the formation of binuclear [Ni 2 (C 9 H 8 O 4)tpmc](ClO 4) 2 •4H 2 O and tetranuclear [Zn 4 (C 9 H 8 O 4)(tpmc) 2 ](ClO 4) 6 • •CH 3 CN•KClO 4 •4H 2 O complexes. In tetranuclear Zn(II) complex bicyclic dicarboxylate ligand is most likely to be bridge coordinated, and in binuclear Ni(II) complex it is coordinated in a combined bridged manner with chelate rings formation. In both complexes macrocyclic ligand was exo coordinated, out of cyclam ring and adopts a boat conformation. The Zn(II) complex is one of the rare tetranuclear Zn(II)-tpmc complexes with carboxylate ion bridging two Zn 2 tpmc units. The complexes were tested for antibacterial activity against Gram-positive bacteria Staphylococcus aureus (ATCC 25923) and Bacillus subtilis (ATCC 6633), Gram-negative bacterium Escherichia coli (ATCC 25922), and yeast Candida albicans (ATCC 10231), and were screened for antiproliferative activity against human cervix adenocarcinoma (HeLa) and human myelogenous leukemia (K562) cell lines.

New cationic tetranuclear Co(II) and neutral binuclear Cu(II) complexes with tpmc (N,N´,N´´,N´´´-tetrakis-(2-pyridylmethyl)-1,4,8,11-tetraazacyclotetradecane) and bridging pyromellitate ligand pma (tetraanion 1,2,4,5-benzenetetracarboxylic acid) were isolated. The composition of the compounds is proposed based on elemental analyses (C, H, N, M = Cu, Co), molar conductivity determination, UV-vis, FTIR, EPR, LC-MS and reflectance spectroscopy, magnetic measurements, cyclic voltammetry, as well as TG and DTA. It is proposed that in [Co 4 (pma)(tpmc) 2 ](ClO 4) 4 •6H 2 O (1), cobalt(II) is six-coordinate out of cyclam rings and one OCOfrom pma participates in coordination with one Co(II). In the case of [Cu 2 (pma)tpmc]•8H 2 O (2), one OCOfrom pma bridges two Cu(II). The cytotoxic activity of 1 and 2 was tested against tumor cell lines human cervix adenocarcinoma (HeLa), estrogenreceptor-positive human breast cancer (MCF-7), human myelogenous leukemia (K562) and the human Caucasian Burkitt's lymphoma (Ramos). The IC 50 values for 1 and 2 were within the range 44.66±2.39 to 152.40±2.28 μM, and from 140.88±3.51 to 192.05±2.09 μM, respectively. Both 1 and 2 were tested for antimicrobial activity. We determined that minimal inhibitory concentration for 1 against Staphylococcus aureus, Bacillus subtilis and Klebsiella pneumoniae was 25 mM. Complex 2 did not express activity against tested microbial strains.

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