The structure of barium aluminate hydrate, 2BaO.5Al2O3.H2O

Abstract

BaAIsHO9, M r = 417.2, hexagonal, P63/mmc, a = 5.635 (3), c = 13.489 (8) A, V= 371.0 (3) A 3, Z = 2, D m = 3.93, D x = 3.733 Mg m -3, MoKa, 2=0.71069A, p=5.967mm -~, F(000)= 388, T= 298 K, R = 0.0693 for 225 independent reflections. This novel compound (obtained by the hydrothermal reaction of barium hydroxide and hydrated alumina, A1203: BaO ratio 2.5, at temperatures >528 K) exhibits a structure related to the well known fl-alumina (Na20.11A1203) structure. The main difference is the absence of two of the oxygen layers from the spinel blocks.

Synthesis and Characterization of a New Layered Barium Aluminate Containing Six-Membered Rings: BaAl2O3(OH)2·H2O

“…Of the nine atoms coordinating to each Ba atom, "ve are the Al-bridging O atoms, two are the O atoms of the terminal OH groups, and the remaining two are the O atoms of two water molecules. These Ba}O distance values are typical for Ba-containing oxide compounds (14,18). The water molecule is H-bonded with two oxygen atoms of the terminal OH groups, and the O 2O (2.849 A > ) and O 2O (2.879 A > ) distances are typical for H-bonds (Fig.…”