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

Abstract

A series of molybdenum(II) compounds [(η5-Cp')Mo(CO)2(L2)][BF4] (Cp' = C5H4(CH2)2SPh, C9H6(CH2)2OMe, L2 = 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 [{η5-C9H6(CH2)2OMe}Mo(CO)2(3,4,7,8-Me4phen)][BF4] (IC50 = 0.7 ± 0.3 μM) and [{η5-C9H6(CH2)2OMe}Mo(CO)2(4,7-Ph2phen)][BF4] (IC50 values 0.8 ± 0.4 μM).