Cytotoxic Activities of Half‐sandwich <i>M</i>(III) Complexes (<i>M</i>=Rh, Ir) Bearing Chloro‐substituted Bidentate‐coordinated Phenanthroline or Terpyridine Ligands

The synthesis and characterization of four compounds [M(η5-C5Me5)(N^N)Cl]PF6 [N^N=4,7-dichloro-1,10-phenanthroline with M=Rh, 1, M=Ir, 2, N^N=4'-(4-chlorophenyl)-2,2':6',2''-terpyridine in the κ2N,N'-coordination mode 3, 4] are described. All were characterized by spectroscopic means their molecular structures crystal confirmed single-crystal X-ray diffraction studies. cytotoxicity all was evaluated MTT assay against three cancer cell lines HeLa (cervical carcinoma), HT-29 (colon adenocarcinoma) MCF-7 (human breast adenocarcinoma). complexes 3 4 display promising activity IC50 values 1 μM. rhodium(III) complex also shows highly improved compared to cisplatin MCF-7. In contrast this, iridium(III) 2 is even less active line than cisplatin.