Imide-Functionalized Fluorenone and Its Cyanated Derivative Based n-Type Polymers: Synthesis, Structure-Property Correlations, and Thin-Film Transistor Performance

The development of high-performance n-type polymer semiconductors is powered by the design and synthesis of electron-deficient building blocks with optimized physicochemical properties. By meticulously installing an imide group onto fluorene and its cyanated derivative, we report here two very electron-deficient building blocks, imide-functionalized fluorenone (FOI) and its cyanated derivative (FCNI), both featuring a deep-lying lowest unoccupied molecular orbital energy level down to -4.05 eV and highly coplanar framework, endowing them ideal units for constructing n-type polymers. Thus, a series of polymers are built from them, exhibiting unipolar n-type transport character with a highest electron mobility of 0.11 cm(2) V-1 s(-1). Hence, FOI and FCNI offer a remarkable platform for accessing high-performance n-type polymers and the imide functionalization of appropriate (hetero)arenes is a powerful strategy for developing polymers with deep-lying LUMOs for n-type organic electronics.

Automated summary

The development of high-performance n-type polymer semiconductors is achieved by designing and synthesizing electron-deficient building blocks. In this study, two electron-deficient building blocks, imide-functionalized fluorenone (FOI) and its cyanated derivative (FCNI), were developed, which exhibit deep-lying lowest unoccupied molecular orbital energy levels and highly coplanar frameworks. A series of polymers were constructed from these building blocks, demonstrating unipolar n-type transport character and high electron mobility. These findings provide a remarkable platform for accessing high-performance n-type polymers and suggest the powerful strategy of imide functionalization for developing n-type organic electronics.