Spirally Configured cis-Stilbene/fluorene (STIF), 10,11-Benzo-, and Imidazole-fused STIF Hybrids as Electron-Transporting Materials for Organic Light-Emitting Diode Applications.

A new class of cis-stilbene/fluorene (STIF) and 10,11-benzo- and imidazole-fused dibenzosuberane/fluorene (Bz-STIF and Imd-STIF) spiro hybrid systems with paired cyanophenyl, pyridyl, and/or pyrimidyl units was synthesized as electron transporting materials (ETMs) for blue fluorescent OLEDs (FOLEDs) and phosphorescent organic light emitting diodes (PhOLEDs). Their photophysical (UV-Vis absorption and emission), electrochemical (E /E ), morphological (glassy transition temperature, T ), and thermal stability (decomposition temperature, T ) properties are systematical compared. Their correlations regarding the effects of the fused unit/substituent(s) in the STIF core on the morphological/thermal stability, HOMO/LUMO energy level, π-electron distribution profiles by DFT calculations, and electron mobility are established.