Synthesis and photophysical characterization of novel electrochemiluminescent dyes

Electrogenerated chemiluminescence, or electrochemiluminescence (ECL), represents one of the most powerful analytical techniques available nowadays for biomedical applications. This is due to several factors, including the nearly absent background signal, high sensitivity, large range of linearity and high spatial and temporal control. As ECL is an electron-hole recombination process, only phosphorescent or Thermally Activated Delayed Fluorescence (TADF) emitters can be used efficiently as they harvest triplet excitons. Purely-organic TADF compounds have been demonstrated to be efficient ECL emitters, offering a cost-effective alternative to expensive phosphorescent heavy metal complexes, which are currently being incorporated into ECL devices and tools. Nevertheless, TADF compounds exhibit limited water solubility and bioconjugability, thus preventing their practical application in ECL. However, TADF compounds exhibit limited water solubility and bioconjugability, which hinders their practical deployment in ECL. This thesis presents the synthesis of novel TADF luminophores and their photophysical and electrochemical characterization, as well as their ECL properties. This is done in order to establish correlations between these properties and to develop a methodology for the design of suitable TADF emitters for ECL applications. Furthermore, the first instances of water-soluble discrete TADF emitters are presented, along with their photophysical and ECL characterization in aqueous media. Finally, the compounds with the highest ECL efficiency will be investigated in Light-Emitting Electrochemical Cells, to ascertain whether a relationship exists between ECL and LEC efficiencies.