Synthesis, characterization and antitumor activity study of some cyclometalated organoplatinum(II) complexes containing aromatic N-donor ligands

A general approach has been designed to synthesize some mononuclear and binuclear cyclometalated platinum(II) complexes, containing aromatic N-donor ligands with the presence of one Cl- trans to carbon. In this way, cyclometalated platinum(II) complex [Pt(C boolean AND N)Cl(dmso)], 1, C boolean AND N = N(1), C(2')-chelated, deprotonated 2-phenylpyridine and dmso = dimethylsulfoxide, was used as a precursor to react with imidazole derivatives (1-methylimidazole, 2a, imidazole, 2b,), monodentate pyridine derivatives (4-methylpyridine, 2c, pyridine, 2d,) and bidentate pyridine derivative (4,4'-bipyridine, 3 and 4,). Synthesized complexes were fully characterized by using multinuclear NMR spectroscopy (H-1, C-13{H-1} and Pt-195), correlation NMR spectroscopy (H-1-H-1 COSY, C-13{H-1}-H-1 Heteronuclear Multiple Quantum Correlation, HMQC, Heteronuclear Multiple Bond Correlation, HMBC, N-15-H-1 HETCOR), elemental analysis, X-ray crystallography and ESI-Mass spectrometry. Antitumor effects of mononuclear cyclometalated platinum(II) complexes 2a, 2c, 2d and 3 were determined on Jurkat, K562, and Raji cell lines and results showed reasonable cytotoxicities. (C) 2011 Elsevier B.V. All rights reserved.