Synthesis, Characterization, and Phosphoesterase Activity of a Series of 4f- and 4d-Sandwich-Type Germanotungstates [(-CH)N]H[(M(HO))(γ-GeWO)] (M = Ce, Nd, Gd, Er, = 7; Zr, = 6).

We report on a family of five new 4f- and 4d-doped sandwich-type germanotungstates with the general formula [(-CH)N]H[(M(HO))(γ-GeWO)]·3(CH)CO (M = Ce, Nd, Gd, Er, = 7; Zr, = 6), which have been synthesized at room temperature in an acetone-water mixture. Among the compound series, , which has been obtained in the presence of 30% HO, represents the first example of a 4d-substituted germanotungstate incorporating the intact dilacunary [γ-GeWO] building block. All compounds were characterized thoroughly in the solid state by single-crystal and powder X-ray diffraction (XRD), IR spectroscopy, thermogravimetric analysis (TGA), and elemental analysis and in solution by NMR and UV-vis spectroscopy. The phosphoesterase activity of and toward the model substrates 4-nitrophenyl phosphate (NPP) and ,-dimethyl -(4-nitrophenyl) phosphate (DMNP) was monitored with H- and P-NMR spectroscopy revealing an acceleration of the hydrolytic reaction by an order of magnitude ( = 3.44 (±0.30) × 10 min for and = 5.36 (±0.05) × 10 min for ) as compared to the uncatalyzed reaction ( = 2.60 (±0.10) × 10 min). demonstrated improved antibacterial activity toward (MIC 32 μg/mL), compared to the unsubstituted POM (MIC 64 μg/mL).