8-Quinolinolate complexes of yttrium and ytterbium: molecular arrangement and fragmentation under laser impact

Abstract

New 8-quinolinolate (Q) complexes of yttrium (1) and ytterbium (2) were synthesized by the reactions of Cp₃Y and Yb[N(SiMe₃)₂]₃ with 3 equiv. of 8-hydroxyquinoline in a DME solution. Single crystal X-ray analysis revealed the trinuclear molecular structure of the compounds Ln₃Q₉. The LDI-TOFMS investigation displayed that under the laser impact the compounds split off Q⁻ anions to give Ln₃Q₈⁺, Ln₂Q₅⁺ and LnQ₃⁺ moieties. In the negative mode spectra the anions Q⁻ and LnQ₄⁻ were observed. The DFT calculations showed the decreased stability of cationic Ln-quinolinolate as compared with their anionic counterparts. Complex 2 which is used as an emitter in a three-layer OLED displayed a metal-centered emission at 979 nm and an intensity of 50 μW cm⁻² at 15.5 V.