Tuning the Emission Color of Cyclometalated Iridium ;Complex by Extending the pi-Electron Delocalization of the Aromatic Chromophore: Synthesis, Photophysical Properties, and X-Ray Crystal Structure

The authors report the preparation, crystal structure, and emission properties of Ir(btq)(2)(acac)(btq = 2-benzo[4,5-]thienylquinoline) (1). The compound has been characterised by UV-vis, fluorescence, MALDI-TOF, and H-1 and C-13 NMR spectroscopy. The crystal structure was also elucidated by X-ray diffraction methods. Its characteristics in terms of optical and structural properties are compared with the reported cyclometalated Ir(III) complex Ir(btp)(2)(acac) (2) (btp = 2-benzo[4,5-]thienylpyridine). Complex 1 shows 53 nm red-shift emission compared to the related complex 2.