Fluorescence energy diagram

Figure Bl.1.3. State energy diagram for a typical organic molecule. Solid arrows show radiative transitions A absorption, F fluorescence, P phosphorescence. Dotted arrows non-radiative transitions.

Figure 3. Energy diagram for 1064 nm excitation of PuFg(g). The 5f electron states of PuF6 are shown at the left. The solid arrows Indicate photon absorption or emission processes. The wavy arrows indicate nonradiative processes by which excited states of PuF6 are lost. Comparison of observed fluorescence photon yields versus the fluorescence quantum yield expected for the 4550 cm" state indicate that the PuFg state initially populated following 1064 nm excitation may dissociate as shown.

Fig. 1 Simplified energy diagram showing the influence of molecular relaxations (with lifetime tr) on the energies of LE and ICT states. The ICT states can be strongly stabilized in polar media by orientation of surrounding dipoles resulting in substantial shifts of fluorescence spectra to lower energies (longer wavelengths)...

Fig. 3.4. Potential energy diagram of DMABN (top) the reaction coordinate contains both solvent relaxation and rotation of the dimethylamino group. Room temperature fluorescence spectrum in hexane and tetrahydrofurane (bottom) (adapted from Lippert et al., 1987).

Figure 3.1 Schematic energy diagram for phosphorescence and fluorescence.

Fig. 2. Potential energy diagram for photoassociation illustrating origin of excimer and molecular fluorescence bands.

Figure 12.1—Energy diagram comparing fluorescence and phosphorescence. Short arrows correspond to internal conversion without the emission of photons. Fluorescence is an energy transfer between states of the same multiplicity (spin state) while phosphorescence is between states of diiferent multiplicity. The situation is more complex than that shown by this Jablonski diagram.

Figure 23-14 Potential energy diagram for the ground state S0 and the first excited singlet S, and triplet Tj states of a representative organic molecule in solution. G is a point of intersystem crossing Sj —> T,. For convenience in representation, the distances r were chosen rS() < rSj < rT thus, the spectra are spread out. Actually, in complex, fairly symmetric molecules, rS(. rs < rT and the 0-0 absorption and fluorescence bands almost coincide, but phosphorescence bands are significantly displaced to the lower wavelengths. From Calvert and Pitts,2 p. 274.

The observable kinetics of a luminescence can be derived from the energy diagram of Figure 3.32. This shows a simple example of two competing decay paths, fluorescence from Si to S0, and a non-radiative transition from Sj to Tj. These are two first-order processes of rate constants and kisc respectively so that the quantum yield of fluorescence is given by the branching ratio as... 

Fig. 2.9. Empirical energy diagram for DMABN in n-butyl chloride (energetics based on room-temperature fluorescence band maxima and on activation energies). In the small-barrier case, E. is to be viewed as a dynamical activation energy resulting from solvent viscosity. The Franck-Condon ground state (after emission from A ) is anomalously destabilized (large E3).

Figure 4-2. Potential energy diagram of the Hg(3P,) + Cl2 reaction. The entrance channel (on the left) and the exit channel (HgClB2X + -> X + fluorescence) are indicated.

Fig. 16.9 (a) Concept of higher photon confinement at the tip apex by a nonlinear optical process. Efficiency of a first-order process such as spontaneous Raman or fluorescence directly reflects the field distribution at the tip apex while the efficiency of a second-order process such as SHG or SFG and a third-order process such as CARS shows further confinement due to the nonlinear response of the material, (b) Energy diagram of CARS process... 

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