ic7b02855_si_001.pdf (678.78 kB)
High-Temperature, High-Pressure Hydrothermal Synthesis, Crystal Structure, Thermal Stability, and Solid State NMR Spectroscopy of an Aluminum Borate, Ba[AlB4O8(OH)]
journal contribution
posted on 2018-01-20, 17:29 authored by Chun-Chi Peng, Hsin-Kuan Liu, Kwang-Hwa LiiA new
aluminum borate, Ba[AlB4O8(OH)], has been synthesized
under high-temperature, high-pressure hydrothermal conditions at 550
°C and 1400 bar and its structure characterized by single-crystal
X-ray diffraction, IR, and MAS 11B, and 27Al
NMR spectroscopy. It crystallizes in the monoclinic space group P21/n with a = 7.0695(5) Å, b = 15.108(1) Å, c = 7.0746(5) Å, β = 93.593(2)°, and Z = 4. Its 2D layer structure is formed of corner-sharing
B4O8(OH) clusters and AlO4 tetrahedra
with the charge-compensating Ba2+ cations between the layers.
While the same in the framework composition, the title compound and
the hydrate, Ba[AlB4O8(OH)]·H2O, differ greatly in structure. Although the title compound contains
an OH group, it is thermally stable up to 740 °C and then decomposes
into Ba2Al2B8O17, as indicated
by high-temperature DSC/TG analysis and powder X-ray diffraction.