Detailed Molecular and Structural Analysis of Dual Emitter IrQ(ppy)2 Complex

Abstract

The molecular structure of the 8-hydroxyquinoline–bis (2-phenylpyridyl) iridium (IrQ(ppy)2) dual emitter organometallic compound is determined based on detailed 1D and 2D nuclear magnetic resonance (NMR), to identify metal-ligands coordination, isomerization and chemical yield of the desired compound. Meanwhile, the extended X-ray absorption fine structure (EXAFS) was used to determine the interatomic distances around the iridium ion. From the NMR results, this compound IrQ(ppy)2 exhibits a trans isomerization with a distribution of coordinated N-atoms in a similar way to facial Ir(ppy)3. The EXAFS measurements confirm the structural model of the IrQ(ppy)2 compound where the oxygen atoms from the quinoline ligands induce the splitting of the next-nearest neighboring C in the second shell of the Ir3+ ions. The high-performance liquid chromatography (HPLC), as a part of the detailed molecular analysis, confirms the purity of the desired IrQ(ppy)2 organometallic compound as being more than 95%, together with the progress of the chemical reactions towards the final compound. The theoretical model of the IrQ(ppy)2, concerning the expected bond lengths, is compared with the structural model from the EXAFS and XRD measurements.

Orange/red light emitting iridium(III) organometallic complexes containing 2,3‐di(pyridine‐2‐yl)quinoxaline as ancillary ligand and their anticancer properties

“…S2, supplementary information) were assigned to the two aromatic CÀ H protons ortho to the coordinated "C" of ppy ligands. [32,33] A similar assignment of the two most up-field peaks of Ir2-Ir4 (Fig. S6, S10 &S14, supplementary information) was attributed to the same protons of the respective cyclometallating ligands, though an overlap of one of the peaks with another proton was noticed in Ir4.…”

“…at 6.4–6.0 ppm of Ir1 ( Fig. S2 , supplementary information) were assigned to the two aromatic C−H protons ortho to the coordinated “C” of ppy ligands [32,33] . A similar assignment of the two most up‐field peaks of Ir2 – Ir4 (Fig.…”

Special Issue: Carbon–Refractory Metal Nanostructures: Synthesis, Characterization and Applications

“…This trans effect leads to an isomer with the C- and N-donor atoms having a trans position to each other. The most efficient organometallic compounds are formed from ortho-metalated carbon-based ligands with superior properties compared with ancillary carbon-based ligands [ 5 ]. Another combination of elements has been investigated, and the prospects of iron oxide films and their sulfidation for dye-sensitized solar cells (DSSCs) were reviewed.…”