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New near-IR electroluminescent complexes of Pr3+, Nd3+, Ho3+, Er3+, Tm3+, Yb3+with N,O-chelated ligands, Ln2(OON)6(OON = 2-(2-benzoxyazol-2-yl)phenolate) and Ln2(SON)6(SON = 2-(2-benzothiazol-2-yl)phenolate), were synthesized by the reaction of Ln[N(SiMe3)2]3and the corresponding N,O-chelating ligand. X-Ray analysis for the Pr and Nd compounds reveals centrosymmetric dimeric structures of the complexes. The solid-state electronic absorption spectra and the electroluminescent spectra show long-wavelength 4f–4f transitions which provide potential use of the compounds as NIR emitting materials in organic light-emitting devices (OLEDs). When constructing OLEDs based on Ln2(OON)6and Ln2(SON)6, the best results were achieved with the Nd3+and Yb3+complexes, where the NIR wall plug efficiency of the ITO/TPD/Ln-complex/BATH/Yb system is 0.82 and 1.22 mW W−1, respectively. [ABSTRACT FROM AUTHOR]

The first monomeric anhydrous scandium tris(8-quinolinolate) complex 1with the 2-amino-8-quinolinolate ligands and the Sc2Q6dinuclear complex 2with the unsubstituted 8-quinolinolate ligands have been synthesized and characterized by X-ray analysis and DFT calculations. The intramolecular hydrogen bonds appear to be responsible for the unique monomeric structure of complex 1. The DFT-based analysis of the electron density topology reveals the (3,−1) critical points corresponding to the OH and NH bonds. The two scandium atoms in compound 2are inequivalent due to different ligand surroundings. They are coordinated by seven (5O, 2N) and eight (4O, 4N) ligand atoms. The increase in the coordination number is accompanied by a decrease in the positive charge of the metal atom as evidenced by the DFT calculations. [ABSTRACT FROM AUTHOR]