An In‐Situ Cyanidation Strategy To Access Tetracyanodiacenaphthoanthracene Diimides with High Electron Mobilities Exceeding 10 cm 2  V −1  s −1

A family of novel highly π‐extended tetracyano‐substituted acene diimides, named as tetracyanodiacenaphthoanthracene diimides (TCDADIs), have been synthesized using a facile four‐fold Knoevenagel condensation strategy. Unlike conventional cyano substitution reactions, our approach enables access to a large π‐conjugated backbone with the in‐situ formation of four cyano substitutents at room temperature while avoiding extra cyano‐functionalization reactions. TCDADIs decorated with different N‐alkyl substituents present good solubility, near‐coplanar backbones, good crystallinity, and low‐lying lowest unoccupied molecular orbital energies of −4.33 eV, all of which contribute to desirable electron‐transport performance when applied in organic field‐effect transistors (OFET). The highest electron mobility of an OFET based on a 2‐hexyldecyl‐substituted TCDADI single crystal reaches 12.6 cm 2 V −1 s −1 , which is not only among the highest values for the reported n‐type organic semiconductor materials (OSMs) but also exceeds that of most n‐type OSMs decorated with imide units.