Conjugated donor-acceptor copolymers from dicyanated naphthalene diimide

A series of donor-acceptor (D-A) alternating copolymers including P(2CNNDI-T), P(2CNNDI-TT), P(2CNNDI-BT), and P(2CNNDI-BDT) based on dicyanated naphthalene diimide (2CN-NDI) in backbones were presented and characterized in this contribution. Their structures were unambiguously identified by NMR spectra. Optical and electrochemical measurements revealed that their LUMO energy levels are substantially lowered at about −4.4 eV by the substitution of electron-deficient cyano groups on the backbone of as-synthesized polymers. And the HOMO levels varied from −6.15 eV to −5.70 eV as a reflection of electron-donating ability of combined thiophene derivatives. The moderate electron-transporting characteristics under ambient conditions based on these dicyanated polymers indicated their promising applications as air-stable electron transporting semiconductors in future electronics.

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