High-pressure synthesis and crystal structure of the mixed-cation borate Ga₄In₄B₁₅O₃₃(OH)₃

Abstract

The mixed cation triel borate Ga4In4B15O33(OH)3 was synthesized in a Walker-type multianvil apparatus at high-pressure/high-temperature conditions of 12.5 GPa and 1300°C. Although the product could not be reproduced in further experiments, its crystal structure could be reliably determined via single-crystal X-ray diffraction data. Ga4In4B15O33(OH)3 crystallizes in the tetragonal space group I41/a (origin choice 2) with the lattice parameters a = 11.382(2), c = 15.244(2) Å, and V = 1974.9(4) Å3. The structure of the quaternary triel borate consists of a complex network of BO4 tetrahedra, edge-sharing InO6 octahedra in dinuclear units, and very dense edge-sharing GaO6 octahedra in tetranuclear units.

Al5B12O25(OH) and Ga4InB12O25(OH) – two additional triel borates with the structure type M 5B12O25(OH) (M = Ga, In)

“…Obviously, the structure of M 5 B 12 O 25 (OH) (M = Ga, In) is quite flexible concerning the incorporation of different metal cations. In subsequent experiments, we were able to additionally synthesize a mixed-cation variation with the formula Ga 4 InB 12 O 25 (OH) which represents the second known borate hosting indium and gallium on different crystallographic positions besides the recently published Ga 4 In 4 -B 15 O 33 (OH) 3 [5]. Actually, the structural motif we found in M 5 B 12 O 25 (OH) (M = Ga, In) had previously been observed in different variations in other compounds like e. g. Ti 5 B 12 O 26 [6] and CaMg 2 P 6 O 3 N 10 [7].…”

“…In the following, the syntheses, crystal structures and IR spectrometric data of the new isotypic compounds Al 5 3 •5H 2 O 1 (99.99% chemPUR) were weighed in with H 3 BO 3 in a stoichiometric ratio of 4:1:12. Both mixtures were thoroughly ground and encapsulated in platinum foil.…”