Diarylfluorenes-based π-stacked molecules: synthesis, X-ray crystallography, and supramolecular light-emitting devices

A series of intramolecular π-stacked molecules as new-concept supramolecular organic semiconductors have been designed by means of the ortho-substituted steric hindrance of diarylfluorenes and facile synthesized via the key step of BF3·Et2O-mediated Friedel–Crafts reaction of carbinols. Their intramolecular π–π stacking interactions were corroborated by the X-ray crystallography, NMR, as well as theoretical simulation. The supramolecular organic light-emitting devices exhibited an anomalous electroluminescence with a maximum luminance of ca. 1282 cd/m2, a luminous efficiency of 0.24 cd/A, and a turn-on voltage of 9 V. The π-stacked semiconductors are potential models of supramolecular semiconductors and optoelectronics.