An In-Situ Cyanidation Strategy To Access Tetracyanodiacenaphthoanthracene Diimides with High Electron Mobilities Exceeding 10 cm2 V-1 s-1

A family of novel highly & pi;-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 & pi;-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.

Automated summary

A series of novel highly π-extended tetracyano-substituted acene diimides (TCDADIs) were synthesized using a simple four-fold Knoevenagel condensation strategy. These compounds have a large π-conjugated backbone and in-situ formation of four cyano substituents, avoiding extra cyano-functionalization reactions. TCDADIs with different N-alkyl substituents exhibit good solubility, near-coplanar backbones, good crystallinity, and low-lying lowest unoccupied molecular orbital energies, leading to desirable electron-transport performance in organic field-effect transistors (OFETs). 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 among the highest values for reported n-type organic semiconductor materials (OSMs).