Prof. Thomas Strassner
Organic Colloquium
Technical University Dresden
Department of Chemistry and Food Chemistry
Description
Title: Blue OLED Emitters: Cyclometalated Platinum- and Iridium NHC Complexes
Abstract: Organic Light Emitting Diode (OLED) displays stand out as one of the most important developments in display technology. OLEDs offer vibrant, energy-efficient, and flexible displays utilized in a wide array of products, from smartphones to large-scale television screens. Organometallic complexes are used to enhance the efficiency, color purity, and durability of these displays.
Our research team has been studying heavy metal-based emitters with cyclometalated N-heterocyclic carbenes (NHC), so-called C^C* ligands, as they can induce strong spin-orbit coupling (SOC) to facilitate the intersystem crossing process from the singlet to triplet excited states, and to promote radiative deactivation from the triplet excited state through phosphorescence with high radiative decay rate constants and photoluminescence quantum yields (PLQY).
This presentation will focus on the synthesis and characterization of mono- and bimetallic luminescent platinum(II) and iridium(III) complexes. As the photophysical properties, efficiencies and stabilities of these phosphorescent emitters strongly depend on the ligand structures we have explored different motifs to fine-tune the photophysical properties. DFT calculations were used to predict promising modifications and to analyze the emissive states.
We recently synthesized novel monometallic C^C* cyclometalated platinum(II) amidinate complexes – previously considered to be inaccessible – as well as photophysically active complexes based on spirobifluorene and spiroxanthene building blocks, which will be discussed in the talk.
