The triclinic form of dipotassium cobalt(II) bis­(dihydrogendiphosphate) dihydrate

In the title compound, K2Co(H2P2O7)2·2H2O, the octa­hedrally coordinated Co2+ ion lies on an inversion centre. Two bidentate dihydrogendiphosphate anions form the equatorial plane of the [CoO6] octa­hedron which is completed by two water mol­ecules in axial positions. This results in isolated {Co(H2O)2[H2P2O7]2}4− entities linked into a three-dimensional network through K—O bonds and O—H⋯O hydrogen-bonding inter­actions involving the dihydrogendiphosphate anions and water mol­ecules. The dihydrogendiphosphate anion, (H2P2O7)2−, is bent and shows an almost eclipsed conformation

Poly[ethane-1,2-diammonium tetra-μ-chlorido-cadmate(II)]

The framework of the title compound, {(NH3CH2CH2NH3)[CdCl4]}n, is built upon layers parallel to (100) made up from corner-sharing [CdCl6] octa­hedra. NH3CH2CH2NH3 2+ cations are situated between the layers and are linked to the layers via an N—H⋯Cl hydrogen-bonding network. The Cd atom is located on an inversion centre and the coordination environment is described as highly distorted octa­hedral

Adsorption of Chromium (VI) on Calcium Phosphate: Mechanisms and Stability Constants of Surface Complexes

The adsorption of chromate on octacalcium phosphate (OCP) was investigated as a function of contact time, surface coverage, and solution pH [...