π-Conjugated alternating copolymer based on the 3,5-dinitro-9-fluorenone for electron-acceptor type materials

Poly(3,5-dinitro-9-fluorenone-alt-9,9-dioctylfluorene) was synthesized from 2,7-dibromo-3,5-dinitro-9-fluorenone. This polymer shows high electron-accepting property compared with its non-substituted counter part, poly(9-fluorenone-alt-9,9-dioctylfluorene). This polymer also exhibits interesting absorption behavior based on the existence of high-energy intramolecular charge transfer interaction between new electron-accepting and common donating moieties and “keto-defects” character.