Six new compounds [(CpTi)XW11O39]n− (Cp=η5-C5H5, X=Ge, Ga, B) have been prepared and their Keggin
structures determined by elementary analysis, IR, UV, H1 NMR and W183 NMR spectrometry. The results
show that the complexes retain Keggin structure. The complexes exhibit antitumoral activity in vitro as shown by MTT experiment.