Asymmetrically decorated POM framework formed by a chiral polyanion

Reactions of NaH₂AsO₄ with C-type polyanion precursor lead to a new compound, (NH₄)₁₅[As₂Fe₆Mo₂₂O₈₅AsO₂(OH)₂]·31.5H₂O (1). Compound 1 was characterized by elemental analysis, infrared spectra, thermogravimetric analysis, and single-crystal X-ray diffraction. Structural analysis reveals that AsO₂(OH)²⁻ asymmetrically decorated the POM framework, constituting the first inorganic anion asymmetrically decorating a POM. AC measurements of the frequency-dependent χ′′ below 5 K indicated a slow magnetization relaxation in 1, resembling typical single-molecule-magnet behavior. Photocatalytic experiments indicated that introduction of AsO₂(OH)²⁻ may offer new active sites and enhanced the overall photocatalytic activity compared with the C-type precursor.