1995 Volume 5 Pages 161-166
Dicalcium cyclo-tetra-μ-imido-tetraphosphate octahydrate has been prepared by adding aqueous calcium chloride into an aqueous cyclo-tetra-μ-imido-tetraphosphoric acid solution. When the cyclo-tetra-μ-imido-tetraphosphate was heated, release of the water of crystallization was observed and a small decomposition of the imidophosphate occurred up to 210°C. The imidophosphate decomposed to produce many kinds of condensed phosphates with or without NH and NH2 groups at a higher temperature. The sample finally changed to calcium metaphosphate.