Serendipitously, an acetonitrile solution of 2 in the presence of excess DABCO formed colorless crystals upon standing overnight. An X-ray diffraction study of these crystals revealed a neutral, doubly zwitterionic adduct of P2O5 and two molecules of DABCO (3, Figure ). The structure of 3 shows a P-N bond distance of 1.84 Å, in close agreement with an expected P-N single bond length of 1.82 Å. Formation of 3 by reaction of 2 with DABCO formally produces an equivalent of the monoanionic adduct of DABCO and [PO3] -. However, 31 P{ 1 H} NMR of the supernatant solution after precipitation of 3 shows a complex mixture of oligophosphate species. The corresponding quinuclidine adduct of metaphosphate has been transiently observed in aqueous solution by 31 P{ 1 H} NMR and was found to rapidly convert to TriMP. However, TriMP is not a significant component of the mixture of phosphates we observed. Additionally, 3 is only poorly soluble in dichloromethane and chloroform, but 31 P{ 1 H} NMR spectroscopy indicated the presence of an impurity which we assigned as 4 but were unable to separate (see below, Figure ). Interested in the potential phosphorylation reactivity of 3, we sought to develop an easy and large scale synthesis of of this compound for further reactivity studies.