A Donor−Acceptor Dyad with a Highly Lewis Acidic Boryl Group

A donor−π−acceptor dyad with a highly electron-deficient B(C6F5)2 group as the acceptor has been
prepared. 5-Diphenylamino-5‘-bis(pentafluorophenyl)boryl-2,2‘-bithiophene (3) was fully characterized
by multinuclear NMR spectroscopy, mass spectrometry, and X-ray crystallography. The solid-state structure
of 3 shows the presence of multiple π-stacking interactions rather than Lewis acid−base bonding between
boron and nitrogen. Cocrystallized benzene molecules are incorporated into a channel-like framework of
3. The electronic structure and photophysical properties were investigated by UV−visible absorption
and emission spectroscopy and DFT calculations. The absorption and emission maxima experience a
strong bathochromic shift relative to the non-fluorinated analogues, the origin of which has been further
examined by DFT calculations.