Synthesis and thermal dehydration of hexaaquarhodium(III) phosphates

Complex salts [Rh(H 2 O) 6 ]PO 4 ( I ) and [Rh(H 2 O) 6 ]PO 4 · H 2 O ( II ) were obtained. Dehydration processes of compounds I and II were studied by thermogravimetry and differential scanning calorimetry. The heat effect for the loss of 0.82 ± 0.01 H 2 O (hydration) molecule was found to be 54 ± 1 kJ/mol, while that for the loss of coordinated H 2 O is 47 ± 1 kJ/mol (for I ) and 43 ± 1 kJ/mol (for II ). The solid phases of dehydration products were studied by X-ray powder diffraction, IR and 31 P MAS NMR spectroscopy, and they were found to be polymers.