Calcium pyrophosphate (Ca2P2O7) → Tricalcium Phosphate

HRID 2267973Notes

Reaction equation

O.O.[P:3]([O-:7])([O-:6])([O-:5])=[O:4].[Ca+2:8].[Ca+2].C1C2[C@@H]3C=C[C@H](C2C=C1)C3.[N+]([O-])([O-])=O.[Ca+2].[N+]([O-])([O-])=O.[O-:29][P:30]([O:33]P([O-])([O-])=O)(=[O:32])[O-:31].[Ca+2].[Ca+2]>OP([O-])([O-])=O.OP([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O.[Mg+2].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[Fe+2]>[P:3]([O-:7])([O-:6])([O-:5])=[O:4].[Ca+2:8].[P:30]([O-:33])([O-:32])([O-:31])=[O:29].[Ca+2:8].[Ca+2:8]

Participants

Conditions

Temperature: 500 °C

Procedure

Example 1 was repeated with the addition of 10.00 g dicalcium phosphate dihydrate, DCPD, CaHPO4.2H2O (Aldrich Chemical Co., Inc. #30,765-3, CAS #7789-77-7) to the homogeneous solution following endothermic dissolution of the calcium nitrate salt. The DCPD was present both as suspended solids and as precipitated material (no agitation used). Warming of the sample to >25° C. initiated an exothermic reaction as described in Example 1, resulting in the formation of a white, pasty solid. Heat treatment and X-ray diffraction of this solid were conducted as described in Example 1. Following heat treatment in air at 500° C. for 1 hour, XRD indicated the solid to be composed of whitlockite as the primary phase along with calcium pyrophosphate (Ca2P2O7) as the secondary phase.

Workup

customas precipitated material (no agitation
temperatureWarming of the sample to >25° C.
customan exothermic reaction
customresulting in the formation of a white, pasty solid
temperatureHeat treatment and X-ray diffraction of this solid

Sources & evidence

ORD record: ord-a00ca8851e8247a29f0c00caa531ca4c
Source dataset: uspto-grants-2001_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06325987B1

Reaction notes

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