In: Chemistry
Explain what electrochemiluminescence (ECL) is give an example of an ECL mechanism
Luminescence is the generation of light from a substance by a chemical reaction (chemiluminescence), light (fluorescence or phosphorescence), or by biological reactions in living cells (bioluminescence).
Electrochemiluminescence (ECL) the luminescence produced during electrochemical reactions in solutions. In ECL, electrochemically generated intermediates change to an electronically excited state that then emits light upon relaxation to a lower-level state. This wavelength of the emitted photon of light corresponds to the energy gap between these two states.
It involves the generation of species at electrode surfaces that then undergo electron-transfer reactions to form excited states that emit light. In this process, electrical energy is converted into radiative energy. At the surface of an electrode, reactive intermediates are produced from stable precursors. These intermediates then react by different pathways to produce light.
In 1972, ECL from Ru(bpy)32+ in acetonitrile using tetrabutylammonium tetrafluoroborate (TBABF4) as the electrolyte. ECL can take place via various mechanisms which include: Annihilation ECL, Coreactant ECL etc. ECL is observed in both inorganic and organic systems.