Luminescence excitation spectra

The luminescence excitation spectra shown in Fig. 8 do not clarify the picture although one can observe the same rank ordering in the emission intensity (measured at Ams = 505 nm) as with the emission spectra except for the D2 molecule having the lowest value. This appears plausible considering that if interaction effects were essentially localized between two adjacent aromatic groups the behavior of the large ring should be very similar to that of the short linear molecule. 

The measured quantities are the emission and absorption (or luminescence excitation) spectra. It is considered that the lowest band in the absorption spectrum is related to the energy difference between the ground state 4f and the excited state 4f° 5d, AE = Eabs- Considering further that for the luminescence related to 4f 5d 4f", Eem = T abs 2SHco, one obtains following relation for the pressure rate of the emission energy ... 

Figure 8.16 Luminescence excitation spectra - Dg excitation at 579.32 nm (emission at 628 27nm) ofS.OmM Eu(STHP) in 20.0mM MESand WOmMNaClatpH 6.6, with addition of DEP showing little change of excitation peak (a) and a decrease in the excitation peak upon addition of MP (b). Reproduced with permission from [8]. 2011, American Chemical Society...

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