Silylene‐Copper‐Amide Emitters: From Thermally Activated Delayed Fluorescence to Dual Emission.

Herein, we report the inaugural instance of N‐heterocyclic silylene (NHSi)‐coordinated copper amide emitters (2–5). These complexes exhibit thermally activated delayed fluorescence (TADF) and singlet‐triplet dual emission in anaerobic conditions. The NHSi‐Cu‐diphenylamide (2) complex demonstrates TADF with a very small ΔEST gap (0.01 eV), an absolute quantum yield of 11 %, a radiative rate of 2.55×105 s−1, and a short τTADF of 0.45 μs in the solid state. The dual emissive complexes (3–5) achieve an absolute quantum yield of up to 20 % in the solid state with a kISC rate of 1.82×108 s−1 and exhibit room temperature phosphorescence (RTP) with lifetimes up to 9 ms. The gradual decrease in the intensity of the triplet state of complex 3 under controlled oxygen exposure demonstrates its potential for future oxygen‐sensing applications. Complexes 2 and 3 have been further utilized to fabricate converted LEDs, paving the way for future OLED production using newly synthesized NHSi‐Cu‐amides. [ABSTRACT FROM AUTHOR]