Thiophene copolymers with other electron-deficient heterocycles

7 Thiophene copolymers with other electron-deficient heterocycles 

decreased steric repulsion within the bithiophene units results in bathochromic shifts of the PL and EL, changing the emission color from green (104) to deep red (106). 

Simple pyridine units have also been explored in copolymers 109 and 110 [149]. The conjugation break at the meffl-linked pyridine unit confines the conjugation and limits the emission color in the blue region (420 and 489 nm for 109 and 110, respectively) in solution, with some red shift (to 510-514 nm) in films. The device 1TO/109/A1 device showed voltage-independent green EL (Xmax = 550 nm, CIE x,y = 0.35, 0.58) at bias 10-18 V. 

6 Oligomers and polymers with thiophene-5 5-dioxide moiety 

Incorporation of electron-deficient thiophene 5,5-dioxide units in electron-rich conjugated oligomers (114) predictably results in a decrease in the material s bandgap. This allows both the absorption and PL energies to be varied over a wide range ( max 310-540 nm, 400-725 nm) to cover the 

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