The high-pressure cadmium borate Cd6B22O39 center dot H2O

摘要

Single crystals of the hydrous cadmium borate Cd6B22O39 center dot H2O were obtained through a high-pressure/high-temperature experiment at 4.7 GPa and 1000 degrees C using a Walker-type multianvil apparatus. CdO and partially hydrolyzed B2O3 were used as starting materials. A single crystal X-ray diffraction study has revealed that the structure of Cd6B22O39 center dot H2O is similar to that of the type M6B22O39 center dot H2O (M = Fe, Co). Layers of corner-sharing BO4 groups are interconnected by BO3 groups to form channels containing the metal cations, which are six- and eight-fold coordinated by oxygen atoms. The compound crystallizes in the space group Pnma (no. 62) [R1 = 0.0379, wR2 = 0.0552 (all data)] with the unit cell dimensions a = 1837.79(5), b = 777.92(2), c = 819.08(3) pm, and V = 1171.00(6) angstrom(3). The IR and Raman spectra reflect the structural characteristics of Cd6B22O39 center dot H2O.