Syntheses, electrochemical and photophysical properties of biphenyl containing conjugated copolymers

Poly 4-(biphenyl-4-yl)-4′-tert butylspiro[benzo[d]imidazole-2,1′-cyclohexane] (P1), Poly 4-(biphenyl-4-yl)-2-dodecyl-2H-benzo[d][1,2,3]triazole (P2), Poly(4-(5-(biphenyl-4-yl)-4-hexylthiophen-2-yl)-2-dodecyl-7-(4-hexylthiophen-2-yl)-2H-benzo[d][1,2,3]triazole (P3) were synthesized via Suzuki cross coupling polycondensation reaction. Polymers are thermally stable with decomposition temperatures above 300 °C. Electrochemical and optical studies revealed that P2 and P3 exhibit reversible redox behavior with multichromic properties. Polymers showed highly fluorescent properties both in thin film and solution forms. Photoluminescence quantum efficiencies of P2 and P3 are 0.70 and 0.57 in chloroform respectively.