pH-Controlled One Pot Syntheses of Giant Mo 2 O 2 S 2 -Containing Seleno-Tungstate Architectures.

Self-assembly reactions of Na2 WO4 , SeO2 /SeO3 2- , and [Mo2 O2 (μ-S)2 (H2 O)6 ]2+ give, depending on the pH value, two new large polyoxometalate complexes: i.e., [(γ-Se2 W14 O52 )3 (Mo2 O2 (μ-S)2 (H2 O)2 )6 ]24- (1) isolated at pH 3.5 and [(γ-Se2 W14 O52 )4 (WO3 (H2 O))8 (W2 O5 )2 (W4 O12 )2 (Mo2 O2 (μ-S)2 (H2 O)2 )4 (Mo2 O2 (μ-S)2 (SeO3 ))4 ]36- (2) isolated at pH 2. Both compounds were characterized in the solid state by single-crystal X-ray diffraction, EDX, elemental analysis, TGA, and FT-IR and in solution by ESI-MS and NMR.