On the synthesis and characterization of layered antimony(III) phosphate and its interaction with moist ammonia and amines

Abstract Samples of antimony(III) phosphate, a layered material, were prepared at room temperature, using the two allotropic forms of Sb 2 O 3 , layered valentinite and cubic senarmontite. The compounds were characterized by infrared spectroscopy, X-ray diffraction, and thermogravimetric–differential thermal analysis. Solids exposed to ammonia, ethylenediamine, or hydrazine vapors also were studied. The interaction between SbPO 4 and the bases always led to the formation of stoichiometric amounts of Sb 2 O 3 and hydrogen phosphate(–2) salts of the bases. With ammonia, the SbPO 4 raw materials gave rise to valentinite or senarmontite, depending on which Sb 2 O 3 allotropic form was used to prepare antimony phosphate. This effect was modified when the SbPO 4 preparations were preheated at 600°C, in which case, a mixture of both forms was obtained. With ethylenediamine and hydrazine, SbPO 4 of whatever origin always gave rise to senarmontite. No evidence of intercalation in the interlayer region of SbPO 4 was obtained.