First insights into the novel class of organometallic compounds bearing a bidentate selenopyridone coordination motif: Synthesis, characterization, stability and biological investigations

Abstract

A series of seven piano–stool complexes featuring selenopyridones as Se,O-chelating ligands was synthesized and characterized. The resulting complexes bear either a p-cym Ru/Os or Cp* Rh/Ir fragment attached to a bidentate selenopyridone ligand. In accordance with recent findings for closely related thiopyridone complexes, dimerization in protic solvents was observed for these compounds. However, these organometallics revealed surprises regarding stability, as well as biological activity. In contrast to analogous thiopyridone organometallics, some of the synthesized complexes were prone to quick ligand dissociation. However, four examples exhibited sufficient stability in aqueous solution to justify further biological investigations. Therefore, MTT assays were carried out for the stable derivatives in three different cancer cell lines. Cytotoxicity trends based on the utilized metal center of the organometallic moiety were observed and compared to the corresponding thio-analogs.