Transient spectral hole-burning and excitation line narrowing in the 3MLCT transitions of [Zn(2,2′-bipyridine)3](ClO4)2:Ru(II)

Transient spectral hole-burning is shown to be a sensitive technique to probe the lowest-excited 3MLCT states of [Ru(bpy)3]2+ doped in [Zn(bpy)3](ClO4)2. The results are consistent with and complementary to excitation line narrowing experiments performed on 0.5, 0.2 and 0.01% [Ru(bpy)3]2+ doped [Zn(bpy)3](ClO4)2 crystals and a 0.5% [Ru(bpy-h8)3]2+ doped [Ru(bpy-d8)3](ClO4)2 crystal.