The effect of substitution on the cytotoxicity of molybdenum(II) and tungsten(II) compounds

A series of allyl molybdenum [(η3-C3H5)Mo(CO)2L2Cl], [(η3-C3H4COOMe)Mo(CO)2L2Br], cyclopentadienyl molybdenum [(η5-C5H4R)Mo(CO)2L2][BF4] (R = H, 4-MeOC6H4CH2, 3,4,5-(MeO)3C6H2CH2), indenyl molybdenum [(η5-C9H6R)Mo(CO)2L2][BF4] (R = H, 4-MeOC6H4CH2) and cyclopentadienyl tungsten compounds [(η5-C5H5)W(CO)2L2][BF4], where L2 is N,N′-chelating ligand, were synthesized and characterized. The in vitro assay on human leukemia cells MOLT-4 has shown that the substitution in the π-ligand has lower effect of on cytotoxicity than exchange of the N,N′-chelating ligand. Nevertheless, even this modification can lead to considerable enhance of cytotoxicity as was evidenced on the series of the indenyl molybdenum(II) compounds.