Cover Feature: Li₂Eu₃Br₂[BO₃]₂: A New Europium(II) Halide Oxoborate with Yellow Luminescence (Z. Anorg. Allg. Chem. 23‐24/2020)

Abstract

The cover picture shows a schematic representation of the bright yellow luminescence performed by title compound Li2Eu3Br2[BO3]2 upon excitation with ultraviolet light. This characteristic emission can be attributed to two crystallographically distinguishable Eu2+ cations residing in eight‐ and ninefold coordination of either two Br– anions and six oxygen atoms from four [BO3]3– triangles or four Br– anions and five oxygen atoms from three [BO3]3– triangles as highlighted in the lower part of the picture. Li2Eu3Br2[BO3]2 forms lemon‐yellow air‐ and water‐stable platelets. Its trigonal crystal structure in space group R3m is described in detail, as well as its paramagnetic behavior fulfilling the Curie‐Weiss law. Three crystallographically different Li+ cations occur in mixed quasi‐octahedral coordination spheres, which should allow for high cationic mobility, justifying the dedication of this article by Jean‐Louis Hoslauer, Falk Lissner, Björn Blaschkowski and Thomas Schleid to the occasion of the 65th birthday of Joachim Maier in May 2020 (http://onlinelibrary.wiley.com/doi/10.1002/zaac.202000227/abstract).