Reinvestigation of the crystal structure of barium cesium cyclotriphosphate dihydrate and vibrational study

GRAPHICAL ABSTRACT

ABSTRACT

In a systematic study of the physico-chemical properties of cyclotriphosphates of alkaline earth cations Type M^IIM^IP₃O₉.xH₂O carried out in our laboratory. (M^II = Ca²⁺, Sr²⁺, and Ba²⁺) and (M^I = Rb⁺, K⁺, Cs⁺, and NH₄⁺). We are interested in the synthesis of the mixed barium cyclotriphosphate associated with the cesium ion.

Chemical preparation and crystal structure are reported for a barium cesium cyclotriphosphate dihydrate BaCsP₃O₉.2H₂O. The phosphoric ring anions are interconnected by BaO₈ dodecahedra in the structure of BaCsP₃O₉.2H₂O. The two water oxygens in the present arrangement participate in the coordination spheres of the associated barium and cesium cations. The thermogravimetric analysis shows that the removal of these two water molecules occurs in two stages between 105 and 600°C. The vibrational study by IR absorption spectroscopy of the title compound reveals the presence of P₃O₉ ring and confirms the existence of nonequivalent positions of water molecules in the structure.

KEYWORDS:

• Barium cesium cyclotriphosphate
• crystal structure
• vibration study