<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Red block crystals of the title compound are prepared by slow evaporation of an aqueous solution containing Co(OAc)<sub>2</sub>, K<sub>8</sub>[γ‐SiW<sub>10</sub>O<sub>36</sub>], NaHCO<sub>3</sub>, and KCl (10 °C, 14 d; 47% yield).</p> </abstract>