Zusammenfassung
Emission spectra and decay times of Ir(ppy)₂(CO)(Cl) dissolved in THF were recorded for 1.2 K =< T =< 300 K. The emission stems from a triplet state T₁ which is split into three substates by less than 1 cm⁻¹. We classify this state as ³LC (ligand centered, ppyππ*) state. At T = 1.2 K, the substates emit independently with three individual decay times (τ(I) = 300 μs, τ(II) = 85 μs, τ(III) = 9 μs) ...
Zusammenfassung
Emission spectra and decay times of Ir(ppy)₂(CO)(Cl) dissolved in THF were recorded for 1.2 K =< T =< 300 K. The emission stems from a triplet state T₁ which is split into three substates by less than 1 cm⁻¹. We classify this state as ³LC (ligand centered, ppyππ*) state. At T = 1.2 K, the substates emit independently with three individual decay times (τ(I) = 300 μs, τ(II) = 85 μs, τ(III) = 9 μs) due to slow equilibration processes, i.e. slow spin-lattice-relaxation, between the substates. With increasing temperature, the emission decay becomes monoexponential as a result of fast equilibration. The results are compared to the spectroscopic behavior
of Ir(ppy)₃ which represents a metal-to-ligand charge transfer ³MLCT emitter.