Synthesis, structure, and characterization of dinuclear copper(I) halide complexes with P^N ligands featuring exciting photoluminescence properties.
A series of highly luminescent dinuclear copper(I) complexes has been synthesized in good yields using a modular ligand system of easily accessible diphenylphosphinopyridine-type P^N ligands. Characterization of these complexes via X-ray crystallographic studies and elemental analysis revealed a dinuclear complex structure with a butterfly-shaped metal-halide core. The complexes feature emission covering the visible spectrum from blue to red together with high quantum yields up to 96%. Density functional theory calculations show that the HOMO consists mainly of orbitals of both the metal core and the bridging halides, while the LUMO resides dominantly on the heterocyclic part of the P^N ligands. Therefore, modification of the heterocyclic moiety of the bridging ligand allows for systematic tuning of the luminescence wavelength. By increasing the aromatic system of the N-heterocycle or through functionalization of the pyridyl moiety, complexes with emission maxima from 481 to 713 nm are obtained. For a representative compound, it is shown that the ambient-temperature emission can be assigned as a thermally activated delayed fluorescence, featuring an attractively short emission decay time of only 6.5 μs at ϕPL = 0.8. It is proposed to apply these compounds for singlet harvesting in OLEDs.
Karlsruhe Institute of Technology, KIT Campus South, Fritz-Haber-Weg 6, D-76131 Karlsruhe, Germany.
Daniel M
DM
Zink
Michael
M
Bächle
Thomas
T
Baumann
Martin
M
Nieger
Michael
M
Kühn
Cong
C
Wang
Wim
W
Klopper
Uwe
U
Monkowius
Thomas
T
Hofbeck
Hartmut
H
Yersin
Stefan
S
Bräse
D003300:Copper / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006219:Halogens / Q000737:chemistry*; D008024:Ligands; D049449:Luminescence; D008958:Models, Molecular; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D009943:Organophosphorus Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry*; D011789:Quantum Theory
D006219:Halogens; D008024:Ligands; D009942:Organometallic Compounds; D009943:Organophosphorus Compounds; D011725:Pyridines; D003300:Copper