Gd4(BO2)O5F – a gadolinium borate fluoride oxide comprising a linear BO2 moiety

Abstract

Abstract Gadolinium borate fluoride oxide Gd4(BO2)O5F crystallises in space group Pmmn (no. 59, a = 1574.6(4), b = 381.42(7), c = 660.88(11) pm, 565 refl., 28 parameters, R 1 = 0.039, wR 2 = 0.128, twin refinement) and comprises linear BO2 − anions between closely packed [GdO] layers formed by OGd4 tetrahedra and terminated by oxygen and fluorine atoms. The crystal structure’s relationship with the NiAs type is illustrated. The Raman spectrum recorded on a single crystal of Gd4(BO2)O5F comprises a single peak at 1364 cm−1 assigned to the only Raman-active vibrational mode ν s of the linear triatomic O–B–O units besides very weak peaks at 805 and 2083 cm−1 (presumably the respective δ and ν as modes).