Fluorinated Phenoxy Boron Subphthalocyanines in Organic Light-Emitting Diodes

Three fluorinated BsubPc s have been synthesized and characterized. Crystals suitable for XRD were grown by slow vapor diffusion and sublimation. Analysis of their crystal structures revealed a dimeric association of BsubPc units for F 5 BsubPc and columnar packing for F 12 BsubPc and F 17 BsubPc . Cyclic volatmmetry (CV) was used to probe the frontier orbital energy levels of these compounds in both dichloromethane and acetonitrile solution; however, only F 5 BsubPc underwent oxidative events, whereas all three compounds underwent reductive events. A −362 and −37 mV shift in the reductive peak potential was observed for peripheral and axial fluorination, respectively, as measured by cyclic voltammetry. Solution UV−vis absorption and photoluminescence spectra were measured in dichloromethane. All three compounds demonstrated air-stable n -type conductivity in single-carrier devices and extremely narrow orange EL emission with a fwhm of only ∼30 nm. F 5 BsubPc showed a maximum luminescence of 122 cd/m 2 at 8 V, with a maximum current efficiency of 0.03 cd/A, whereas the devices fabricated from F 12 BsubPc and F 17 BsubPc produced luminescence with a maximum value of <1 cd/m 2 .