20859-38-5Relevant academic research and scientific papers
Two modifications of NH4HPO3F: Synthesis and crystal structure
Prescott,Troyanov,Kemnitz
, p. 152 - 156 (2008/10/08)
The α and β modifications of NH4HPO3F were synthesized and characterized with single crystal X-ray diffraction. The crystal structure of α-NH4HPO3F determined at 180 K is monoclinic, space group P21/n, with a = 7.4650(1), b = 15.586(2), c = 7.5785(9) A, β = 108.769(9)°, V = 834.9(2) A3, Z = 8, and R1 = 0.0376 and wR2 = 0.0818. β-NH4HPO3F measured ar 310 K crystallizes in the triclinic space group, P1, with a = 7.481(1), b = 7.511(1), c = 7.782(1) A, α = 84.31(1), β = 84.20(1), γ = 68.67(2)°, V = 404.31(9) A3, Z = 4, and R1 = 0.0254 and wR2 = 0.0735. A phase transition was not observed between 180 and 310 K for β-NH4HPO3F. Both modifications of NH4HPO4F consist of HPO3F- and NH4+ units. Two pairs of two unique anions are linked to each other by O-H ... O hydrogen bonds to form cyclic tetramers held together by N-H ... O bonds. No O-H ... F or N-H ... F bonds were observed.
Solid-Phase Interaction of Fluorapatite with Ammonium Hydrogen Difluoride
Laptash, N. M.,Kaidalova, T. A.
, p. 535 - 537 (2008/10/08)
A solid-phase interaction of fluorapatite with ammonium difluoride was studied in the temperature range 25-900°C. At room temperature, calcium fluoride and ammonium dihydrogen phosphate or isostructural ammonium florophosphate were formed as the result of grinding a mixture of theinitial components. Above 200°C, the reaction was accompanied by the formation of a volatile phosphor compound. At the final stage of th e process (above 500°C), glassy ammonium hydrogen ultrafluorophosphate of nonstoichiometric composition was formed, which again yielded fluorapatite upon reaction with calcium fluoride.
