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.