High-pressure synthesis and characterization of the first cerium fluoride borate CeB2O4F

CeB2O4F is the first cerium fluoride borate, which is exclusively built up of one-dimensional, infinite chains of condensed trigonal-planar [BO3]3− groups. This new cerium fluoride borate was synthesized under high-pressure/high-temperature conditions of 0.9GPa and 1450°C in a Walker-type multianvil apparatus. The compound crystallizes in the orthorhombic space group Pbca (No. 61) with eight formula units and the lattice parameters a=821.63(5), b=1257.50(9), c=726.71(6) pm, V=750.84(9) Å3, R1=0.0698, and wR2=0.0682 (all data). The structure exhibits a 9+1 coordinated cerium ion, one three-fold coordinated fluoride ion and a one-dimensional chain of [BO3]3− groups. Furthermore, IR spectroscopy, Electron Micro Probe Analysis and temperature-dependent X-ray powder diffraction measurements were performed. A new rare-earth fluoride borate CeB2O4F could be synthesized under high-pressure/high-temperature conditions of 0.9°GPa and 1450°Cin a Walker-type multianvil apparatus. The crystal structure represents a new structure type in the class of rare-earth fluoride borates. The structure exhibits a 9+1 coordinated cerium ion, one three-fold coordinated fluoride ion and a one-dimensional chain of [BO3]3− groups. A closer view on the ac-plane shows an interesting wave-like modulation of the borate chains. [Display omitted] •CeB2O4F is the first fluoride borate exclusively built up of one-dimensional, infinite chains of condensed trigonal-planar [BO3]3− groups.•CeB2O4F is the first cerium fluoride borate.•High-pressure conditions were necessary to synthesize CeB2O4F.