New macrocyclic Cu(II) complex with bridge terephthalate: Synthesis, spectral properties, in vitro cytotoxic and antimicrobial activity. Comparison with related complexes

Abstract

New cationic mixed-ligand tetranuclear complex [Cu-4(tpht) (tpmc)(2)](ClO4)(6)center dot 5H(2)O (tpmc = N, N', N '', N"'-tetrakis-(2-pyridylmethyl)-1,4,8,11-tetraazacyclotetradecane, H(2)tpht - terephthalic acid (benzene-1,4-dicarboxylic acid)) was prepared and characterized by elemental analysis (C, H, N, Cu), UV/Vis, IR, EPR (X-band) spectra, conductivity, cyclic voltammetry and magnetic measurements (SQUID). Five coordinated geometry for new Cu(II) complex is proposed. The central metal ion is coordinated with two pyridyl and two cyclam nitrogens and bridged with -N-(CH2)(3)-N- fragments of the cyclam ring and OCO- of the terephthalate anion. Copper (II) ions are coordinated out of cyclam rings and one OCO- group from tpht bridges two Cu(II) inside tpmc unit and two Cu(2)tpmc units are bridged by dicarboxylate tpht dianion engaging all four oxygen atoms. Weak ferromagnetic interaction between copper (II) ions in new tetranuclear complex is observed, Weiss constant theta = 0.21 K and C = 0.398 cm(3) Kmol(-1). The new complex, related Cu(II) complexes with bridged benzene carboxylate, [Cu-2(C6H5COO)tpmc](ClO4)(3)center dot CH3OH, [Cu-2(Hpht)tpmc](ClO4)(3)center dot 3H(2)O (H(2)pht = phthalic acid), [Cu-4(ipht) (tpmc)(2)](ClO4)(6)center dot NaClO4 center dot 2CH(3)CN (H(2)ipht = isophthalic acid), solvents, starting salts and ligands were in vitro evaluated for antiproliferative and antibacterial activity. Antiproliferative evaluation was carried out using tumour cell lines: HeLa (human adenocarcinoma) and K562 (chronic myelogenous leukaemia). Among all tested compounds, the ipht complex revealed the highest antiproliferative activity. According to antibacterial screening results, most active compound was the benzoate complex against Micrococcus lysodeikticus.