19-Tungstodiarsenate(III) Functionalized by Organoantimony(III) Groups: Tuning the Structure–Bioactivity Relationship

A family of three discrete organoantimony­(III)-functionalized heteropolyanions[Na­{2-(Me₂HN⁺CH₂)­C₆H₄Sb^III}­As^III₂W₁₉O₆₇(H₂O)]^10– (<b>1</b>), [{2-(Me₂HN⁺CH₂)­C₆H₄Sb^III}₂As^III₂W₁₉O₆₇(H₂O)]^8– (<b>2</b>), and [{2-(Me₂HN⁺CH₂)­C₆H₄Sb^III}­{WO₂(H₂O)}­{WO­(H₂O)}₂(<i>B</i>-β-As^IIIW₈O₃₀)­(<i>B</i>-α-As^IIIW₉O₃₃)₂]^14– (<b>3</b>)have been prepared by one-pot reactions of the 19-tungstodiarsenate­(III) precursor [As^III₂W₁₉O₆₇(H₂O)]^14– with 2-(Me₂NCH₂)­C₆H₄SbCl₂. The three novel polyanions crystallized as the hydrated mixed-alkali salts Cs₃KNa₆[Na­{2-(Me₂HN⁺CH₂)­C₆H₄Sb^III}­As^III₂W₁₉O₆₇(H₂O)]·43H₂O (<b>CsKNa-1</b>), Rb_2.5K_5.5[{2-(Me₂HN⁺CH₂)­C₆H₄Sb^III}₂As^III₂W₁₉O₆₇(H₂O)]·18H₂O·Me₂NCH₂C₆H₅ (<b>RbK-2</b>), and Rb_2.5K_11.5[{2-(Me₂HN⁺CH₂)­C₆H₄Sb^III}­{WO₂(H₂O)}­{WO­(H₂O)}₂(<i>B</i>-β-As^IIIW₈O₃₀)­(<i>B</i>-α-As^IIIW₉O₃₃)₂]·52H₂O (<b>RbK-3</b>), respectively. The number of incorporated {2-(Me₂HN⁺CH₂)­C₆H₄Sb^III} units could be tuned by careful control of the experimental parameters. Polyanions <b>1</b> and <b>2</b> possess a dimeric sandwich-type topology, whereas <b>3</b> features a trimeric, wheel-shaped structure, representing the largest organoantimony-containing polyanion. All three compounds were fully characterized in the solid state via single-crystal X-ray diffraction (XRD), infrared (IR) spectroscopy, and thermogravimetric analysis, and their aqueous solution stability was validated by ultraviolet–visible light (UV-vis) and multinuclear (¹H, ¹³C, and ¹⁸³W) nuclear magnetic resonance (NMR) spectroscopy. Effective inhibition against six different types of bacteria was observed for <b>1</b> and <b>2</b>, and we could extract a structure–bioactivity relationship for these polyanions