Investigation of mixed alkaline earth phosphates. Synthesis and crystal structure of CaBa(HPO4)2: A new mixed alkaline earth hydrogenmonophosphate
1999; Elsevier BV; Volume: 1; Issue: 1 Linguagem: Inglês
10.1016/s1293-2558(00)80061-8
ISSN1873-3085
AutoresL.B. Taker, S. Chabchoub, L. Smiri‐Dogguy,
Tópico(s)Crystal Structures and Properties
ResumoHydrothermal synthesis, IR characterization and X-ray single-crystal structure are reported for CaBa(HPO4)2. It crystallizes in the monoclinic system, space group P21/a (N∘14) with a = 9.470(2) Å, b = 7.930(1) Å, c = 9.865(1) Å, β = 115.78(1)°, V = 667.1(2) Å3 and Z = 4. The refinement of data leads to R = 0.0331 for 1131 observed reflections [I > 4σ(I)]. The crystal structure of CaBa(HPO4)2 is built up from corner-and/or edge-sharing BaO9 polyhedra, CaO7 pentagonal bipyramids and (H)PO4 tetrahedra giving rise to a three-dimensional network. The HPO42− groups are located in layers parallel to the ab plane at z ~ 0 and z ~ 1/2. Interleaved barium and calcium cations ensure the cohesion between these sheets. Hydrogen bonds contribute to the stability of the structure.
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