High-Temperature, High-Pressure Hydrothermal Synthesis, Crystal Structure, Thermal Stability, and Solid State NMR Spectroscopy of an Aluminum Borate, Ba[AlB4O8(OH)]

Chun-Chi Peng; Hsin-Kuan Liu; Kwang-Hwa Lii

doi:10.1021/acs.inorgchem.7b02855

High-Temperature, High-Pressure Hydrothermal Synthesis, Crystal Structure, Thermal Stability, and Solid State NMR Spectroscopy of an Aluminum Borate, Ba[AlB₄O₈(OH)]

Inorg Chem. 2018 Feb 5;57(3):1545-1549. doi: 10.1021/acs.inorgchem.7b02855. Epub 2018 Jan 22.

Authors

Chun-Chi Peng¹, Hsin-Kuan Liu¹, Kwang-Hwa Lii^{1

2}

Affiliations

¹ Department of Chemistry, National Central University , Zhongli, Taiwan 320, Republic of China.
² Institute of Chemistry, Academia Sinica , Taipei, Taiwan 115, Republic of China.

PMID: 29355308
DOI: 10.1021/acs.inorgchem.7b02855

Abstract

A 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.