Vibrational Study and Crystal Structure of Barium Cesium Cyclotriphosphate Dihydrate

Abstract

Chemical preparation, crystal structure, thermal behavior, and IR studies are reported for the barium cesium cyclotriphosphate dihydrate BaCsP3O9.2H2O and its anhydrous form BaCs4(PO3)6. BaCsP3O9.2H2O, isotypic to BaTlP3O9.2H2O and BaNH4P3O9.2H2O, is monoclinic P21/n with the following unit cell dimensions: a = 7.6992(2)Å, b = 12.3237(3)Å, c = 11.8023(3)Å, α = 90 (2) , β = 101.18(5) , γ = 90. (3) , and Z = 4. The total dehydration of BaCsP3O9.2H2O is between 100 C and 580 C. The IR absorption spectroscopy spectrum for the crystal confirms that most of the vibrational modes are comparable to similar cyclotriphosphates and to the calculated frequencies. The thermal properties reveal that the compound is stable until 90 C.