Dihydrogen Tetrametaphosphate: A Potent Precursor to New Organo and Metallo Phosphate Species


Solid-state cyclic phosphate acids have potential applications as precursors for novel organo and metallo cyclic phosphate species. In addition, they also possess phosphorus atoms in the highest oxidation state which confers oxidation resistance and potential to be good catalysts for oxidation reactions.

Problem Addressed

Despite some recent progress in applying cyclic phosphates in materials science and conventional coordination chemistry, their fundamental chemical properties remain poorly understood. One of the reasons for this limited understanding is the dearth of robust precursors to synthesize these compounds. Existing cyclic phosphate precursors have been documented, but the furnace conditions required to synthesize these compounds limited their accessibility. This invention describes a simple preparation method for dihydrogen tetrametaphosphate -- a potent precursor for a wide range of cyclic phosphates -- that can improve its accessibility.


Dihydrogen tetrametaphospate can be prepared by reacting [PPN]4[P4O12]·5H2O with one equivalent of trifluoroacetic anhydride (TFAA) in acetone at 23 ℃. This reaction, which can be easily carried out at the gram-scale under open-air conditions is capable of producing dyhydrogen tetrametaphospate as an analytically pure solid at 93% yield. Other strong acids, including trifluoroacetic acid, triflic acid, and triflate anhydride can be used as alternatives to TFAA in this reaction scheme.


  • Preparatory reaction for dihydrogen tetrametaphosphate can be easily carried out at the gram-scale under open-air conditions