Mn0.95I0.02[PO3(OH)] · 2H2O phosphate–iodate, an inorganic analogue of phosphonates

Abstract

The new Mn0.95I0.02[PO3(OH)] · 2H2O phosphate–iodate (space group Pnam = Pnma, D 2h 16 ) is obtained under hydrothermal conditions. The crystal structure is determined without preliminary knowledge of the chemical formula. The structure consists of layers of MnО6 octahedra connected with PO4 tetrahedra. Water molecules are located between the layers. [IO3]– groups having a typical umbrella-like coordination are statistically implanted in layers of MnО6 octahedra at a distance of 1.2 A from Mn atoms. Their content in the crystal is minor. The structures of the phosphate–iodate coincides with the structures of phosphonates with consideration for the replacement of one (OH) vertex of the РО4 tetrahedron by the organic methyl radical СН3. In the structures of phosphonates and earlier studied phosphates, identical layers are distinguished and the cause of the existence of two MDO varieties is established based on the analysis within the OD theory. Possible hybrid structures derived from the prototypes under consideration are predicted.