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.

本研究通过酸催化取代蒽的苯并环化反应，合成了两种新型扭曲多环芳烃（polycyclic aromatic hydrocarbons, PAHs）1和2。该两种异构体展现出迥异的光物理与氧化还原性质，其中化合物2的最高占据分子轨道-最低未占据分子轨道（HOMO–LUMO）能隙远小于化合物1。固态下，化合物2以独特的二维人字形堆积基元排列，可使其在有机场效应晶体管（Organic Field-Effect Transistor, OFET）器件中实现高效双极性电荷传输——这是此前在扭曲多环芳烃中尚未被观测到的特性。与之相对，化合物1采取一维二聚化π堆叠结构排列，并表现出绝缘特性。