Cyclic(amino)(barrelene)carbene metal amide complexes: Synthesis and thermally activated delayed fluorescence
Year: 2024
Type: article
Abstract: Carbene-metal-amide (CMA) complexes based on cyclic(amino)(barrelene)carbene (CABC) ligands have been prepared for both Cu(I) and Au(I) metal centres. Synthetic protocols based on the conventional and microwave heating enabled ten-fold shorter reaction times and high yields of the CMA materials. Stabilization of the lowest unoccupied molecular orbital (LUMO) effects the electronic and photophysical properties. These materials benefit from short excited state lifetimes down to 0.9 μs and photoluminescence quantum yields up to 66 %. Nonradiative processes are revealed and associated with the rotational freedom of the aryl moiety in the CABC carbene ligand. Steady-state and time-resolved photoluminescence spectroscopy was used to estimate an activation energy barrier of 83 meV between singlet and triplet charge transfer (CT) excited states. Varied temperature photoluminescence confirms that 3 CT photoluminescence remains even at 18 K, with no contribution from locally excited triplet states 3 LE. Molecular design rules have been enhanced to propose bright thermally activated delayed fluorescence (TADF) CMA emitters.
Source: Organic Electronics
Authors: Charlotte Riley, William Jones, Nguyen Le Phuoc, Mikko Linnolahti, Alexander S. Romanov
Institutions: University of Manchester, University of Eastern Finland
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,540
Award: G3363691081
OpenAlex ID: W4404124782