Cyclopentadienyl Molybdenum(II) Compounds Bearing Ether and Thioether Functions in the Side Chain: Synthesis, Characterization, and Cytotoxic/Cytostatic Studies.

A series of molybdenum(II) compounds [(η -Cp')Mo(CO) (L )][BF ] (Cp'=C H (CH ) SPh, C H (CH ) OMe, L N,N-chelating ligand) have been synthesized and characterized by spectroscopic and analytical methods including X-ray crystallography. The in vitro assay on human leukemia cells MOLT-4 has shown that the substitution in the π-ligand in combination with suitable N,N-chelating ligand can lead to species with cytotoxicity considerably higher than reported to cisplatin. Unusually high activity was observed for compounds bearing phenanthroline ligands [{η -C H (CH ) OMe}Mo(CO) (3,4,7,8-Me phen)][BF ] (IC =0.7±0.3 μM) and [{η -C H (CH ) OMe}Mo(CO) (4,7-Ph phen)][BF ] (IC values 0.8±0.4 μM).