New luminescent 10-oxybenzoquinolate complexes of rare earth metals

A series of Sc, Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Ho, Er, Tm and Yb complexes with oxybenzoquinoline ligands (BQ) was synthesized by the reactions of 10-hydroxybenzo[h]quinoline with cyclopentadienides or tris(trimethylsilyl)amides of rare earth metals. The structure, as well as the photo-and electrolumi-nescent (PL, EL) properties of these complexes in solutions and solid state were studied. In solutions, complexes of sodium and lanthanides exhibit double peaked ligand-centered PL of enol and keto forms of BQ with a quantum yield of 1%-8%. In the solid state the complexes of Sm, Eu, Ho, Nd, Er, and Yb along with the ligand-centered PL also exhibit a moderate-intensity metal-centered PL which is characteristic of the corresponding Ln3 thorn ions. Sc(BQ)3 complex shows bright green EL which has intensity comparable to the best results observed for scandium complexes with other organic ligands.& COPY; 2022 Chinese Society of Rare Earths. Published by Elsevier B.V. All rights reserved.