Multiexponential Relaxation in Water

COMPARISON OF CONTINUOUS AND TWO-STATE RELAXATION Advanced Topic  

The ftinction A(p t) describes the time-independent of the emission spectrum which shifts in time along the P axis. The time-resolved decays of intensity are ftinctions of both the emission maximum at time r[Pcg(t)] and the wavenumber that is observed (V). Calculation of the steady-state spectra for this model is moderately difficult. Such calculsuions require integration over all times  

The presence of a time-dependent spectral shift requires numerical procedures. For the continuous model, the TRES all show the same spectral distribution and halfwidth, exc for the shifting esnission maximum. 

An alternative model is the discontinuous two-state model. This is formally equivalent to the two-statereactioo described in Chapter 18. The emission of the initial state is assumed to be centered at This state is assumed to change into a relaxed state with a rate constant l/t. Both states are assumed to return to the ground state with a rate constant but, in genecal these rates can be unequal for the F and R states. Tlie emission of die relaxed state is centered at Vjf. 

Experimental Distinction iietween Continuous and Two-Stale Relaxation 

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