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

Abstract 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 ΔE ST gap (0.01 eV), an absolute quantum yield of 11 %, a radiative rate of 2.55×10 5 s −1 , and a short τ TADF 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 k ISC rate of 1.82×10 8 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.