The Incorporation of Dicarboxylates into Octacalcium Bis(hydrogenphosphate) Tetrakis(phosphate) Pentahydrate

Octacalcium bis(hydrogenphosphate) tetrakis(phosphate) pentahydrate (OCP) has been found to complex with saturated aliphatic dicarboxylate ions, CnH2nC2O42−; n=1–6. These organic substances were incorporated, instead of HPO42−, into the “B-layer” of the OCP structure. The incorporation caused expansion in the basal spacing (d100) of OCP from 18.7 Å to 19.6–26.1 Å. A possible structural model is proposed for the incorporation.