A 2 nm Molecular Ladder with a Twisted Backbone

Molecular
ladders are of particular interest for their well-defined
fused-ring architectures as promising materials in organic electronics.
Herein, we present the synthesis and properties of a molecular ladder
featuring 4-fold antiaromatic pentagonal rings embedded into the 2.000(1)
nm backbone. The crystallographic analysis revealed its twisted backbone,
causing tight packing with a shortest contact of 3.210(9) Å.
The robust redox behavior of up to 3e– oxidation
and 4e– reduction originates from the diindenonaphthalene
and diindenotetracene characters, respectively. This ladder exhibited
a maximum hole mobility of μh = 0.035 cm2 V–1 s–1 in single-crystal
organic field-effect transistors.

分子梯（Molecular ladders）因其结构明确的稠环架构，作为有机电子领域极具潜力的功能材料而广受关注。本文中，我们报道了一种嵌入2.000(1) nm主链的含4个反芳香性五元环的分子梯的合成方法与理化性质。晶体学分析显示其主链呈扭曲构型，由此形成紧密堆积，最短分子间接触距离为3.210(9) Å。该化合物具备优异的氧化还原性能：最高可发生3电子氧化与4电子还原，分别源自二茚并萘（diindenonaphthalene）与二茚并四苯（diindenotetracene）的结构特征。在单晶有机场效应晶体管中，该分子梯展现出最高达0.035 cm²·V⁻¹·s⁻¹的空穴迁移率。