<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>The title compound is synthesized by hydrothermal reaction of Sb<sub>2</sub>O<sub>3</sub>, Na<sub>2</sub>WO<sub>4</sub>, CuCl<sub>2</sub>, and en (autoclave, 160 °C, 6 d; 30% yield based on Sb<sub>2</sub>O<sub>3</sub>).</p> </abstract>