Synthesis, characterization and biological activity of organotitanium substituted heteropolytungstates

Abstract

Eight new compounds α- and β-M_xH_y[(CpTi)₃XW₉O₃₇]·nH₂O (M = K⁺, x = 4, y = 3; M = NBu₄⁺, x = 7, y = 0; X = Si, Ge) have been synthesized from vacant heteropolytungstate precursors α-, β-[XW₉O₃₄]¹⁰⁻ (X = Si, Ge) and Cp₂TiCl₂. The products were characterized by elemental analysis, IR, UV–VIS spectroscopy, ¹H NMR, ¹⁸³W NMR spectroscopy and polarography. ¹⁸³W NMR spectra of the complexes support the stoichiometry of the new heteropolyanions and the probable retention of the A-XW₉ units in water. The organotitanium substituted complexes showed promising activity in two human tumor cell lines in vitro.