TY - JOUR AU - Sun, Qinchao AU - Mosquera-Vazquez, Sandra AU - Lawson Daku, Latevi Max AU - Guénée, Laure AU - Goodwin, Harold A. AU - Vauthey, Eric AU - Hauser, Andreas TI - Experimental Evidence of Ultrafast Quenching of the 3MLCT Luminescence in Ruthenium(II) Tris-bipyridyl Complexes via a 3dd State PY - 2013 JF - Journal of the American Chemical Society JA - J. Am. Chem. Soc. SN - 0002-7863 VL - 135 IS - 37 SP - 13660 EP - 13663 L1 - http://pubs.acs.org/doi/pdf/10.1021/ja407225t L2 - http://pubs.acs.org/doi/full/10.1021/ja407225t L3 - http://pubs.acs.org/doi/abs/10.1021/ja407225t L4 - http://www.unige.ch/sciences/chifi/publis/pics/double/ref01373.png M3 - 10.1021/ja407225t UR - http://dx.doi.org/10.1021/ja407225t N2 - Ultrafast transient absorption spectroscopy serves to identify the 3dd state as intermediate quencher state of the 3MLCT luminescence in the non-luminescent ruthenium complexes [Ru(m-bpy)3]2+ (m-bpy = 6-methyl-2,2′-bipyridine) and [Ru(tm-bpy)3]2+ (tm-bpy = 4,4′,6,6′-tetramethyl-2′,2′-bipyridine). For [Ru(m-bpy)3]2+, the population of the 3dd state from the 3MLCT state occurs within 1.6 ps, while the return to the ground state takes 450 ps. For [Ru(tm-bpy)3]2+, the corresponding values are 0.16 and 7.5 ps, respectively. According to DFT calculations, methyl groups added in the 6 and 6′ positions of bipyridine stabilize the 3dd state by ∼4000 cm–1 each, compared to [Ru(bpy)3]2+. ID - 1373 ER -