Two metal-pipemidic acid complexes modifying Keggin polyoxometalates

Two new organic-inorganic hybrid compounds based on Keggin polyoxometalates (POMs) and the quinolone antibacterial, pipemidic acid (HPPA), {[Cu(PPA)(2)](2)[H3PMo12O40]}center dot 8H(2)O (1), and {[Zn(PPA)(2)][H3PMo12O40]}center dot[HPPA]center dot 3H(2)O (2) have been synthesized under hydrothermal conditions and structurally characterized. In 1, Keggin POMs combine with two chelate Cu(PPA)(2) complexes forming a discrete seesaw-like motif, while Keggin POMs combine with the binuclear zinc clusters [Zn-2(PPA)(4)] forming a discrete dumbbell-like motif in 2. Antitumor activities in vitro and the interactions with CT-DNA of the compounds have been investigated by MTT experiment and UV spectra, respectively.