High-Pressure Synthesis and Crystal Structure of Ce(4)B(14)O(27)

Ce(4)B(14)O(27) was synthesized under conditions of 2.6 GPa and 750 °C in a Walker-type multianvil apparatus. The crystal structure was determined on the basis of single-crystal X-ray diffraction data, collected at room temperature, revealing that Ce(4)B(14)O(27) is isotypic to La(4)B(14)O(27). Ce(4)B(14)O(27) crystallizes monoclinically with four formula units in the space group C2/c (No. 15) and the lattice parameters a = 1117.8(2), b = 640.9(2), c = 2531.7(5) pm, and β = 100.2(1)°. The three-dimensional boron-oxygen framework consists of [BO(4)](5–) tetrahedra and trigonal-planar [BO(3)](3–) groups. The structure contains two crystallographically different cerium ions. Furthermore, Raman spectroscopy was performed on single crystals of Ce(4)B(14)O(27).