For a series of seven unsaturated and seven epoxy di-and tricarboxylic acids, pK a a values were determined potentiometrically in aqueous media at 25 °C and an ionic strength of 0.1 M (NaCl). The thermodynamic pK a a values were correlated with the atomic charges of carboxylic group calculated by the MNDO-PM3 semiempirical MO method.

Seven macrocyclic dinuclear Cu(II) complexes with tpmc = = N, N',N",N'"-tetrakis(2-pyridylmethyl)-1,4,8,11-tetraazacyclotetradecane of coordination formulae [Cu 2 tpmc](ClO 4 ) 4 (1), [Cu 2 (X)tpmc](ClO 4 ) 3 ·nH 2 O, X= F -, n = 0 (2), X = Cl -, n = 1 (3), X = Br -, n = 0 (4), X= I -, n = 1 (5), X = = NO 2 -, n = 0 (6), [Cu 2 (NCS) 2 tpmc](ClO 4 ) 2 (7) were evaluated for their cytotoxic activity against human cervix adenocarcinoma (HeLa), human melanoma (Fem-x) and human colon carcinoma (LS174) cell lines. The results were compared with the corresponding data for the cis-diamminedichloridoplatinum(II) (CDDP) as referent cytostatic, as well as with the free ligands and the solvent dimethyl sulfoxide (DMSO) as controls. The complexes showed considerable antiproliferative effect, although significantly less than CDDP. The thermal decomposition pattern of the complexes was determined by simultaneous TG/DSC measurements. The thermal stability of the compounds 2-7 followed the trend of their antiproliferative activity against the HeLa cell line, as well as their corresponding stability constants. The highest thermal stability and cytotoxicity belonged to complex [Cu 2 tpmc](ClO 4 ) 4 , with no anionic coligand. Complex [Cu 2 (NO 2 )tpmc](ClO 4 ) 3 exhibited a selective cytotoxicity against LS174 cells, at the level of the most active [Cu 2 tpmc](ClO 4 ) 4 .

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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.

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