Ambipolar organic semiconductors are of high interest for organic field-effect transistors. For n-type conduction, low LUMO energies are required. Dibenzo[a,e]pentalenes (DBPs) are promising compounds; however, few derivatives exist with energetically low-lying LUMO levels. Here, we present DBP derivatives with LUMO energies down to −3.73 eV and small bandgaps down to 1.63 eV determined through cyclic voltammetry, UV/vis absorption spectroscopy, and TDDFT calculations. Single-crystal X-ray diffraction analysis revealed a 1D π-stacking mode. The addition of arylalkynyl substituents at the five-membered rings in a facile and versatile synthetic route allowed for tuning of the band gaps and LUMO energies. The synthetic route can easily be modified to access a variety of DBP derivatives. The LUMO energies of the DBP derivatives presented herein make them attractive for an application in n-type or ambipolar field-effect transistors.

中文翻译：

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低层LUMO能级的二苯并[ a，e ]戊烯为潜在的n型材料

双极性有机半导体对有机场效应晶体管非常感兴趣。对于n型传导，需要低LUMO能量。二苯并[ a，e戊烯（DBPs）是有前途的化合物；然而，很少有具有低能量LUMO水平的衍生物存在。在这里，我们介绍了通过循环伏安法，紫外/可见吸收光谱和TDDFT计算确定的具有低至−3.73 eV的LUMO能量和低至1.63 eV的小带隙的DBP衍生物。单晶X射线衍射分析显示出一维π堆叠模式。在五元环上以简便且通用的合成路线添加芳基炔基取代基可调节带隙和LUMO能量。可以轻松修改合成路线以访问各种DBP派生词。本文介绍的DBP衍生物的LUMO能量使其对n型或双极性场效应晶体管的应用具有吸引力。