<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>The title anion is synthesized by reaction of metallic molybdenum dissolved in H<sub>2</sub>O<sub>2</sub>, K<sub>4</sub>P<sub>2</sub>O<sub>7</sub> and Me<sub>4</sub>NCl (H<sub>2</sub>O, 20 °C, 1—2 d; 69% yield).</p> </abstract>