.. _sphx_glr_api_gallery_photochem_jablonski:

Jablonski-diagram kinetics
----------------------------

The 3-state (S1, T1, S0) Jablonski excited-state decay network, checked
against its closed-form population solution, plus triplet
phosphorescence, flash photolysis of the triplet, and Kasha's rule.


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  <div id='sg-tag-list' class='sphx-glr-tag-list'></div>


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    <div class="sphx-glr-thumbnails">

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    <div class="sphx-glr-thumbcontainer" tooltip="jablonski_network builds the 3-state (S1, T1, S0) Jablonski excited-state decay network as a StoichiometricNetwork -- reusing the kinetics domain&#x27;s general mass-action reaction-network engine rather than reimplementing rate-equation integration. The numerical integration is checked here against jablonski_populations_analytic&#x27;s closed-form solution.">

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  .. image:: /api/gallery/photochem/jablonski/images/thumb/sphx_glr_plot_01_jablonski_kinetics_thumb.png
    :alt:

  :doc:`/api/gallery/photochem/jablonski/plot_01_jablonski_kinetics`

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      <div class="sphx-glr-thumbnail-title">Jablonski-diagram excited-state kinetics</div>
    </div>


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    <div class="sphx-glr-thumbcontainer" tooltip="Lewis and Kasha (1944) showed that phosphorescence comes from a triplet state T_1, whose spin-forbidden return to the singlet ground state makes it far slower than fluorescence. Using realistic rate constants (nanosecond fluorescence, millisecond phosphorescence), jablonski_populations_analytic shows the two emissions separated by six orders of magnitude in time, and phosphorescence_quantum_yield gives the fraction of absorbed photons re-emitted from the triplet.">

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  .. image:: /api/gallery/photochem/jablonski/images/thumb/sphx_glr_plot_02_lewis_kasha_triplet_phosphorescence_thumb.png
    :alt:

  :doc:`/api/gallery/photochem/jablonski/plot_02_lewis_kasha_triplet_phosphorescence`

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      <div class="sphx-glr-thumbnail-title">Lewis and Kasha: phosphorescence as slow emission from the triplet state</div>
    </div>


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    <div class="sphx-glr-thumbcontainer" tooltip="Flash photolysis (Norrish and Porter, 1949) excites a sample with an intense, short flash and then records its absorption at a series of delays with a second probe flash, so a short-lived intermediate is seen appearing and disappearing in real time. Here the intermediate is the triplet state of the Jablonski model (~chemistrykit.photochem.jablonski_populations_analytic): the probe measures the triplet-triplet absorbance \Delta A(t)=\varepsilon_T\ell[T_1](t), and fitting the late-time decay of noisy &quot;measured&quot; points recovers the triplet lifetime.">

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  .. image:: /api/gallery/photochem/jablonski/images/thumb/sphx_glr_plot_03_norrish_porter_flash_photolysis_thumb.png
    :alt:

  :doc:`/api/gallery/photochem/jablonski/plot_03_norrish_porter_flash_photolysis`

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      <div class="sphx-glr-thumbnail-title">Norrish and Porter's flash photolysis: watching a transient triplet decay</div>
    </div>


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    <div class="sphx-glr-thumbcontainer" tooltip="Kasha (1950) stated that emission comes almost entirely from the lowest excited state of a given multiplicity (S_1 for fluorescence), because internal conversion from higher states such as S_2 takes picoseconds or less, much faster than emission. With kasha_emission_yields, a molecule excited to S_2 sends only a tiny fraction of its emission from S_2; the exception is a molecule like azulene, whose large S_2-S_1 gap slows internal conversion enough for S_2 emission to compete.">

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  .. image:: /api/gallery/photochem/jablonski/images/thumb/sphx_glr_plot_04_kasha_rule_emission_from_s1_thumb.png
    :alt:

  :doc:`/api/gallery/photochem/jablonski/plot_04_kasha_rule_emission_from_s1`

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      <div class="sphx-glr-thumbnail-title">Kasha's rule: emission comes from the lowest excited state</div>
    </div>


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    </div>


.. toctree::
   :hidden:

   /api/gallery/photochem/jablonski/plot_01_jablonski_kinetics
   /api/gallery/photochem/jablonski/plot_02_lewis_kasha_triplet_phosphorescence
   /api/gallery/photochem/jablonski/plot_03_norrish_porter_flash_photolysis
   /api/gallery/photochem/jablonski/plot_04_kasha_rule_emission_from_s1