The crystal structure of calcium ammonium hydrogenpyrophosphate CaNH₄HP₂O₇

Structure cristalline de 1'hydrogéno bis(dihydrogénopyrophosphate) tripotassique: K3H(H2P2O7)2

“…Si certaines structures de pyrophosphates acides hydrates &aient connues Na2H2POT.6H20 (Collin & Willis, 1971), K2H 2-(P2OT).½H20 (Dumas, Galign6 & Falgueirettes, 1973b), KaHPEOT.3H20 (Dumas, Galign6 & Falgueirettes, 1973a), NaaHPEOT.6H20 (Emmerson & Corbridge, 1973), par contre, aucun sel acide anhydre n'avait 6t6 6tudi~ lorsque ce travail a 6t6 entrepris. Depuis, la structure du sel double CaNH4HP20 7 (Mathew & Schroeder, 1977) a ~t6 publi6e. La d+termination de la structure cristalline de KaH5(P2OT) 2 fut envisag~e pour ~tudier la configuration de l'anion pyrophosphate dans un autre type d'environnement cristallin ot~ existent, en plus des interactions ~lectro-statiques, des liaisons hydrog6ne fortes.…”

Crystal structure of dicalcium potassium trihydrogen bis(pyrophosphate) trihydrate

“…However, it is involved in five hydrogen bonds (two donor, three acceptor) and three O" 9 9 K contacts ( Table 4). The structure of Ca2KH3(P2OT)2"3H20 bears considerable resemblance to that of Ca(NHa)HP207 (Mathew and Schroeder, 1977). The formula of Ca2KH3-(P207)2" 3H20 may be represented by replacement of the two NH 4 ions in 2[Ca(NH4)HP207] by one K ion and one H ion and addition of three water molecules.…”

“…ported the crystal structures of two calcium ammonium pyrophosphates (Mathew and Schroeder, 1977;Takagi et al, 1980). Here we report the crystal structure of dicalcium potassium trihydrogen bis(pyrophosphate) trihydrate, Ca2KH3(P207) 2.…”

BaZn2(HAs2O7)AsO4: A Novel Barium Zinc Arsenate Containing Zn4O16 Clusters and Hydrogen Diarsenate Groups

“…Another interesting feature is the hydrogen diarsenate unit, HAs 2 O 7 , in the structure. A few phosphates such as CaNH 4 HP 2 O 7 , K 2 H 2 P 2 O 7 , and Cs 2 HP 2 O 7 contain hydrogen diphosphate groups. In contrast, compounds containing HAs 2 O 7 groups have not been documented.…”