Synthesis, crystal structures, and photophysical properties of electron-accepting diethynylindenofluorenediones

Abstract

A series of 6,12-bis[(trialkylsilyl)ethynyl]indeno[1,2-b]fluorene-5,11- diones has been synthesized. X-ray crystallographic analysis of these compounds reveals that triisopropylsilyl (TIPS) substitution on the alkyne terminus affords the largest number of intermolecular interactions in the solid state. Conversely, use of trialkylsilyl groups smaller or larger than TIPS furnishes a variety of crystal-packing motifs that contain fewer interactions. Electrochemical and photophysical data suggest that these molecules are excellent electron-accepting materials.© 2011 American Chemical Society.