Iridium(III) complexes with PEO and PS polymer macroligands and light-emitting properties : synthesis and characterization

On the basis of terpyridine functionalized poly(ethylene oxide) (PEO) and poly(styrene) (PS), a series of light-emitting iridium(III) compounds was effectively synthesized. The respective iridium(III) target compounds were prepared by grafting chloro-bridged precursor complexes [Ir(ppy)2--Cl]2 (ppy = phenylpyridine) and [Ir(ppy-CHO)2--Cl]2 (ppy-CHO = 4-(2-pyridyl)benzaldehyde) onto terpyridine functionalized PEO and PS tails. 1D and 2D NMR characterization was performed revealing the expected resonances. Gel permeation chromatography (GPC) proved the stability and purity of the targeted materials. Preliminary investigations of the light-emitting properties were carried out by standard methods such as UV-vis and steady-state luminescence spectroscopy. The morphology and the quality of films of these iridium(III) compounds were furthermore investigated using AFM. Improved stability on the electrode surface was illustrated using cyclic voltammetry. One of the polymer materials was compared to the neat complex, which showed quick degradation.