.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "api/gallery/photochem/stern_volmer/plot_01_stern_volmer.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

    .. note::
        :class: sphx-glr-download-link-note

        :ref:`Go to the end <sphx_glr_download_api_gallery_photochem_stern_volmer_plot_01_stern_volmer.py>`
        to download the full example code.

.. rst-class:: sphx-glr-example-title

.. _sphx_glr_api_gallery_photochem_stern_volmer_plot_01_stern_volmer.py:


Stern-Volmer quenching, and distinguishing static from dynamic mechanisms
=============================================================================

:func:`~chemistrykit.photochem.systems.stern_volmer.stern_volmer_ratio`
gives the linear intensity-ratio-vs-quencher-concentration relationship;
:func:`~chemistrykit.photochem.systems.stern_volmer.fit_stern_volmer`
recovers the Stern-Volmer constant from synthetic data. Measuring both
the intensity-ratio and lifetime-ratio slopes lets
:func:`~chemistrykit.photochem.systems.stern_volmer.classify_quenching_mechanism`
distinguish a purely dynamic (collisional) mechanism from a purely
static (ground-state complexation) one.

.. GENERATED FROM PYTHON SOURCE LINES 16-39

.. code-block:: Python

    import matplotlib.pyplot as plt
    import numpy as np

    from chemistrykit.photochem.systems.stern_volmer import (
        classify_quenching_mechanism,
        dynamic_quenching_constant,
        fit_stern_volmer,
        stern_volmer_ratio,
    )
    from chemistrykit.photochem.visualizers.photochem_plots import plot_stern_volmer

    kq, tau0 = 2.0e10, 5.0e-9  # diffusion-controlled quenching, 5 ns unquenched lifetime
    Ksv = dynamic_quenching_constant(kq, tau0)
    print(f"Ksv (dynamic) = {Ksv:.3f} 1/M")

    Q = np.array([0.0, 0.005, 0.010, 0.020, 0.040])
    intensity_ratio = stern_volmer_ratio(Ksv, Q)
    fit = fit_stern_volmer(Q, intensity_ratio)
    print(f"Fitted Ksv = {fit.Ksv:.3f} 1/M, R^2 = {fit.r_squared:.6f}")

    ax = plot_stern_volmer(Q, intensity_ratio, fit=fit)
    plt.tight_layout()




.. image-sg:: /api/gallery/photochem/stern_volmer/images/sphx_glr_plot_01_stern_volmer_001.png
   :alt: Stern-Volmer plot
   :srcset: /api/gallery/photochem/stern_volmer/images/sphx_glr_plot_01_stern_volmer_001.png
   :class: sphx-glr-single-img


.. rst-class:: sphx-glr-script-out

 .. code-block:: none

    Ksv (dynamic) = 100.000 1/M
    Fitted Ksv = 100.000 1/M, R^2 = 1.000000




.. GENERATED FROM PYTHON SOURCE LINES 40-42

For purely dynamic quenching, the lifetime ratio tracks the intensity
ratio exactly -- the two Stern-Volmer slopes agree.

.. GENERATED FROM PYTHON SOURCE LINES 42-52

.. code-block:: Python

    lifetime_ratio = stern_volmer_ratio(Ksv, Q)  # dynamic: tau0/tau follows the same law as I0/I
    mechanism_dynamic = classify_quenching_mechanism(intensity_ratio_slope=fit.Ksv, lifetime_ratio_slope=Ksv)
    print(f"\nMechanism (equal slopes): {mechanism_dynamic}")

    # For purely static quenching, the lifetime is unaffected (slope 0)
    # even though the intensity ratio still rises linearly.
    mechanism_static = classify_quenching_mechanism(intensity_ratio_slope=fit.Ksv, lifetime_ratio_slope=0.0)
    print(f"Mechanism (zero lifetime slope): {mechanism_static}")

    plt.show()




.. rst-class:: sphx-glr-script-out

 .. code-block:: none


    Mechanism (equal slopes): dynamic
    Mechanism (zero lifetime slope): static





.. rst-class:: sphx-glr-timing

   **Total running time of the script:** (0 minutes 0.043 seconds)


.. _sphx_glr_download_api_gallery_photochem_stern_volmer_plot_01_stern_volmer.py:

.. only:: html

  .. container:: sphx-glr-footer sphx-glr-footer-example

    .. container:: sphx-glr-download sphx-glr-download-jupyter

      :download:`Download Jupyter notebook: plot_01_stern_volmer.ipynb <plot_01_stern_volmer.ipynb>`

    .. container:: sphx-glr-download sphx-glr-download-python

      :download:`Download Python source code: plot_01_stern_volmer.py <plot_01_stern_volmer.py>`

    .. container:: sphx-glr-download sphx-glr-download-zip

      :download:`Download zipped: plot_01_stern_volmer.zip <plot_01_stern_volmer.zip>`


.. only:: html

 .. rst-class:: sphx-glr-signature

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.github.io>`_