Synthesis of carbazole-based scaffolds for self-assembled Pd(II)-cages with TADF properties

This work was aimed to the preparation of new carbazole-type scaffolds decorated with donor and acceptor (D-A) substituents to be employed for the production of the corresponding Pd(II)-based cages. The design of the new molecules was essentially focused to the evaluation of their Thermally Activated Delayed Fluorescence (TADF) properties. A bottom-up method involving the stepwise functionalization – through aromatic nucleophilic substitution (SNAr) followed by Suzuki coupling - of the starting 3,6-dibromo-9H-carbazole was developed. Once the desired organic compounds were obtained, their complexation with Pd(II) was performed in order to prepare the corresponding metalla-cages. All of the desired products showed optoelectronic properties. Absorption and emission spectroscopy was used to evaluate the electroluminescence properties and to characterize the different compounds. Moreover, PLQY and lifetime decays values were also included into the final work in accordance to the estimation of TADF characteristics studies.