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A Jablonski diagram showing the excitation of molecule A to its singlet excited state (1 A*) followed by intersystem crossing to the triplet state (3 A) that relaxes to the ground state by phosphorescence. It was used to describe absorption and emission of light by fluorescents.
Intersystem crossing (ISC) is an isoenergetic radiationless process involving a transition between the two electronic states with different spin multiplicity. [ 1 ] Excited electrons can undergo intersystem crossing to a degenerate state with a different spin multiplicity.
Jablonski diagram indicating intersystem crossing (left) and internal conversion (right). Internal conversion is a transition from a higher to a lower electronic state in a molecule or atom. [1] It is sometimes called "radiationless de-excitation", because no photons are emitted.
A Jablonski diagram describing the sensitization process in triplet-triplet annihilation upconversion. The sensitizer first absorbs light and reaches its first singlet excited state (S 1 ). The sensitizer S 1 state undergoes intersystem crossing (ISC) to the triplet excited state (T 1 ).
However, this occurs on a much slower time scale, being on the order of microseconds to seconds. Thus, usually, thermal activation from the triplet to the excited singlet state, the reverse intersystem crossing, populates the singlet state in a fast process and quenches the triplet state population. As a consequence, delayed fluorescence is ...
Jablonski diagram illustrating the electronic states accessible during photoexcitation. Note: ISC stands for Intersystem Crossing. E 0,0 is a measurement of the energy gap between the ground state and the lowest energy triplet state. This parameter is proportional to the phosphorescence wavelength and is used to compute the redox potentials of ...
Jablonski diagram of an energy scheme used to explain the difference between fluorescence and phosphorescence. The excitation of molecule A to its singlet excited state ( 1 A*) may, after a short time between absorption and emission (fluorescence lifetime), return immediately to ground state , giving off a photon via fluorescence (decay time).
This may be followed by an intersystem crossing wherein the electron undergoes a spin flip, or a radiative or nonradiative decay back to the ground state. [5] Figure 2. A representative Jablonski diagram. One example of an organic compound that undergoes photoisomerization is azobenzene. The structure is two phenyl rings joined with a N=N ...