Various Structural Design Modifications: <i>para</i>-Substituted Diphenylphosphinopyridine Bridged Cu(I) Complexes in Organic Light-Emitting Diodes

The well-known system of dinuclear Cu(I) complexes bridged by 2-(diphenylphosphino)pyridine (PyrPhos) derivatives Cu2X2L3 and Cu2X2LP2 (L = bridging ligand, P ancillary ligand) goes along with endless variation options for tunability. In this work, the influence substituents modifications on phosphine moiety NP-bridging ligand was investigated. previous studies, location lowest unoccupied molecular orbital (LUMO) copper PyrPhos family found to be located enabled color tuning in whole visible spectrum. A multitude based triple methylated 2-(bis(4-methylphenyl)phosphino)-4-methylpyridine (Cu-1b-H, Cu-1b-MeO, Cu-1b-F) up bearing 2-(bis(4-fluorophenyl)phosphino)pyridine (Cu-6a-H) electron-withdrawing fluorine atoms over many other variations ligands were synthesized. Almost all confirmed via single crystal X-ray diffraction analysis. Besides theoretical TDDFT-studies electronic properties photophysical measurements, majority phosphino-modified tested solution-processed organic light-emitting diodes (OLEDs) different heterostructure variations. best results OLED devices obtained emitter Cu-1b-H a stack architecture ITO/PEDOT-PSS (50 nm)/poly-TPD (15 nm)/20 wt % emitter:CBP:TcTA(7:3) (45 nm)/TPBi (30 nm)/LiF(1 nm)/Al (>100 nm) high brightness 5900 Cd/m2 good current efficiency 3.79 Cd/A.