Acceptor or Donor (Diaryl B or N) Substituted Octupolar Truxene: Synthesis, Structure, and Charge-Transfer-Enhanced Fluorescence

Abstract

Two diaryl B- and N-substituted truxene charge-transfer compounds B3 and N3 have been synthesized. The fluorescence intensities of several nonfunctionalized truxene compounds are 1 order of magnitude weaker than that of B3 and N3. To reveal the structure-property correlations, the X-ray structures of B3 and N3 and their precursors 3 and 4 have been determined. The extended molecular dimension, the especially shortened B-C bond, and the improved planarity of B3 can serve as direct structural evidence for the charge transfer.