Selective Formation of cis‐N‐Heterocyclic Carbene‐PtII‐Pnictogen Complexes and in vitro Evaluation of Their Cytotoxic Activities toward Cancer Cells

Abstract

A series of heterotopic platinum complexes combining N‐heterocyclic carbene (NHC) and pnictogen‐based ligands [Pn = P(nBu)3, PPh3, AsPh3 and SbPh3] has been synthesized and fully characterized. Use of an excess of Pn ligand led to the formation of cationic bis‐Pn platinum‐NHC complexes in high yield, with both Pn ligands being arranged trans to each other. Several representative complexes could be characterized by X‐ray crystallographic studies thus confirming the ligand arrangement around the metal. This simple approach allows the generation of diversity in metallodrug candidates. Biological activities on various human cancer cells have been studied and compared with those of cisplatin. The results confirmed the high cytotoxicity of these NHC‐platinum complexes bearing pnictogen ligands.