Synthesis and Characterization of an Emissive Ag(Ⅰ)Complex with a D-A Type Ligand Containing Two Electron-withdrawing Groups
Thermally activated delayed fluorescence(TADF)materials have attracted significant attention in the field of or-ganic light-emitting diodes(OLEDs)due to their tremendous application potential.The outermost electronic configuration of the Ag(Ⅰ)complex is d10 configuration,with d orbitals always being filled.There is no metal-centred(MC)state,therefore the quenching effect caused by the MC state does not occur.This renders it an appropriate choice for the design and development of TADF materials.In this study,we designed and synthesized a novel D-A ligand,9-(4'-(4,6-diphenyl-1,3,5-triazin-2-yl)-4-(3-(pyridin-2-yl)-1H-pyrazole-1-yl)-[1,1'-biphenyl]-2-yl)-3,6-dimethoxy-9H-carbazole(L).The ligand employs 3,6-dimeth-oxy-9H-carbazole as the electron donor and comprises a bis-electron-donating group comprising triazine and pyridyl pyrazole as the electron acceptor.An ionic Ag(I)complex,Ag(L)(POP)(BF4)(1),was synthesised utilising L as a nitrogen-containing bidentate ligand and bis[2-(diphenylphosphino)phenyl]ether(POP)as a phosphorus-containing bidentate ligand.The ligand L and complex 1 were characterised by 1H and 13C nuclear magnetic resonance spectrometry,elemental analysis and X-ray single crystal diffraction analysis.The complex 1 belongs to the triclinic crystal system with space group P-1,with a=1.30213(4)nm,b=1.63383(4)nm,and c=1.93108(5)nm,α=92.941(2)°,β=105.247(3)°,γ=98.591(2)°,V=3.90076(18)nm3.The Ag+ion in complex 1 is tetrahedrally coordinated with a twisted tetrahedral coordination geometry.At room temperature,complex 1 in solid form emits strong green light under UV light,with a maximum at 490 nm.The fluorescence lifetime is 23.0 ns,the thermally activated delayed fluorescence(TADF)lifetime is 503.9 ps,and the photoluminescence quantum yield(PLQY)is 43.8％.The steady-state emission spectra and time-dependent photoluminescent spectra of complex 1 at different temperatures demonstrate that complex 1 exhibits TADF characteristics at room temperature.
Ag(Ⅰ)complexcrystal structurephotoluminescencedensity functional theory calculationthermally activated delayed fluorescence
NETL
NSTL
万方数据
