Synthesis, structure and cytotoxic activity of mixed-valent Cu(I)/Cu(II) salt containing a pyrazolone derivative as ligand

摘要

The compound [Cu(TAMEN)][Cu(NCS)_2Cl](DMF)_2 containing the Mannich base N,N′-tetra-(4-antipyrylmethyl)-1,2-diaminoethane (TAMEN), as ligand, was synthesized and characterized by conductometric, magnetic, electronic and infrared spectroscopic properties. The single-crystal X-ray structure shows the presence of two well defined complex units, [Cu(TAMEN)]~(2+) and [Cu(NCS)_2Cl]~(2-). The complex cation contains copper(II) in the elongated pseudo-octahedral environment created by the N_2O_4 donor set of TAMEN whereas, the counterion exhibits a pseudo trigonal planar geometry around the Cu(I) ion. Both, the pyrazolonic ligand and the complex have been screened for their cytotoxic activity against human tumor cell lines: glioblastoma multiforme, breast cancer, hepatoma and lung carcinoma. The nontumor cell lines MDBK (bovine kidney) and BALB/c 3T3 clone 31 (mouse embryo) were also included in the experiments. In contrast to the ligand TAMEN, the [Cu(TAMEN)][Cu(NCS) _2Cl](DMF)_2 was found to decrease in a time- and concentration-dependent manner the viability of cultured tumor (MCF-7, A549, 8MGBA, Hep G2) and non-tumor (MDBK, BALB/c 3T3) cell lines.