AQUACOMPLEXES OF RARE EARTH ELEMENTS (Ce, Eu, Gd and Yb) WITH -DODECABORATE ANION: SYNTHESIS, STRUCTURE, PROPERTIES

Aquacomplexes M(HO)BH·15HO (M = Eu, Gd, Yb) and Ce(HO)BH·15HO stabilized by -dodecaborate anion have been synthesized by neutralization of (HO)BH solution with rare earth element (REE) oxides MO (M = Eu, Gd, Yb) and CeO and characterized. The structures of Eu(HO)BH·15HO and Ce(HO)BH·15HO have been determined by X-ray diffraction analysis. It was found that the reaction in the CeO/(HO)BH system is accompanied by the redox transformation Ce → Ce, while for the MO (M = Eu, Gd, Yb)/(HO)BH systems, stabilization of the oxidation state of the corresponding REE has been observed. The luminescent properties of Ce(HO)BH·15HO have been studied. It was shown that this compound emits in the near ultraviolet region with an emission maximum at 370 nm.