Non-radiative processes of excited CT states of Ru(II) and Pt(II) compounds and excited d-d states of Rh(III) compounds in the solid state and at higher temperatures

Radiative and non-radiative processes of excited CT states of Ru(II) and Pt(II) compounds and excited d-d states of Rh(III) compounds in the solid state and at higher temperatures are examined. A rapid non-radiative transition of a metal-to-ligand charge transfer excited state to the ground state does not occur over a wide temperature range (77-300 K) for [Ru(bpy)₃](PF₆)₂ and [Pt₂(tpy)₂(guanidinato)](ClO₄)₃. Spectral simulations of the d-d emissions of Rh(III) compounds in the range 77-536 K are carried out by assuming a simple configuration coordinate. The large Huang-Rhys factors indicate that the lowest and second lowest d-d excited states of Rh(III) compounds are strongly coupled to the excited vibrational state of the ground state. The frequency factors of non-radiative decay are 10¹¹-10¹² s^-1 for the excited triplet state.