Chemists have been studying cyclic polyphosphates since the 1800s, but unlike their linear analogs, little is known about their chemical properties and reactivity. In a bid to change that, Christopher C. Cummins of MIT and coworkers have developed a previously unknown organic-soluble acid form of tetrametaphosphate (J. Am. Chem. Soc.2014, DOI: 10.1021/ja5058339). Polyphosphates are linear or cyclic oxyanions formed from PO4units linked together by sharing oxygen atoms. Common linear examples are di- and triphosphates found in ADP and ATP involved in biochemical energy storage and in nucleotides important in protein and lipid synthesis and carbohydrate metabolism. The linear versions also are useful components of detergents and flame retardants. But chemists have never fully unraveled the secrets of how to use cyclic polyphosphates because they tend to be stable only in aqueous systems. The MIT team made the organic-soluble dihydrogen oxyanion by treating tetrametaphosphate with trifluoroacetic anhydride in wet acetone and pairing it with a lipophilic triphenylphosphineiminium cation. The new reagent reacts with tin and chromium amides to make the first reported tetrametaphosphate metal complexes and with methanol to form a methyl ester, showing that phosphorylations of amino acids and nucleosides with cyclic polyphosphates are feasible.