5,5′‐Diazaisoindigo: an Electron‐Deficient Building Block for Donor–Acceptor Conjugated Polymers

Abstract A novel electron‐deficient building block, 5,5′‐diazaisoindigo ( 5DNIID ), was synthesized through a facile method in good yield. As a derivative of isoindigo, 5DNIID shows an ultra‐low LUMO level of −3.92 eV after incorporation of two electron‐deficient nitrogen atoms into the para ‐position of the amine groups in the isoindigo π skeleton. Modified polymerization conditions were applied to efficiently afford the donor–acceptor (D–A) conjugated polymer 5DNIID‐2T , which exhibited a p‐type charge transport property.