Synthesis and Crystal Structure of the New High-Pressure Phase CdB2O4

• Published in: Chemistry : a European journal Vol. 14; no. 20; pp. 6149 - 6154
• Main Authors: Knyrim, Johanna S., Emme, Holger, Döblinger, Markus, Oeckler, Oliver, Weil, Matthias, Huppertz, Hubert
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 01.01.2008; WILEY‐VCH Verlag
• Subjects: borates; electron diffraction; high-pressure chemistry; multianvil; structure elucidation
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.200800506

The use of high‐pressure/high‐temperature conditions (7.5 GPa and 1100 °C; Walker‐type multianvil apparatus) led to the synthesis of a new cadmium borate CdB2O4, starting from stoichiometric mixtures of the oxides. The crystal structure was determined on the basis of single crystal X‐ray diffraction data, to reveal the hexagonal space group P63 with a=885.2(2), c=716.72(8) pm, Z=8, R1=0.0178, and wR2=0.0388 (all data). CdB2O4 is built up from interconnected layers of BO4‐tetrahedra and exhibits for the first time the basic structure of a family of compounds, represented by BaGa2O4, KAlSiO4, KGeAlO4, KCoPO4, CaP2N4 and the recently discovered SrP2N4. The lack of superstructure ordering in CdB2O4 was confirmed by electron diffraction. Additionally, a BOB angle of 180° was found in this borate for the first time. Borates under pressure! CdB2O4 (see figure) was synthesised under high‐pressure conditions and exhibits for the first time the basic structure of the family of compounds represented by BaGa2O4, KAlSiO4, KGeAlO4, CaP2N4, KCoPO4, and SrP2N4.