Synthesis and Divergent Electronic Properties of Two Ring-Fused Derivatives of 9,10-Diphenylanthracene

Two new contorted polycyclic aromatic
hydrocarbons (PAHs) 1 and 2 were synthesized
by acid-catalyzed benzannulation
of a substituted anthracene. The isomers reveal dissimilar photophysical
and redox properties with 2 having a much smaller HOMO–LUMO
gap than 1. In the solid state, 2 packs
in a unique two-dimensional herringbone motif that gives rise to efficient
ambipolar charge transport in OFET devices, a feature not previously
observed in contorted PAHs. On the other hand, 1 packs
in one-dimensional dimerized π-stacks and displays insulating
properties.