Soft-lithography patterning of functionalized regioregular polythiophenes

Poly(3-(6-thiohexyl)-4'-dodecyl-2,2'-bithiophene) (1) was successfully synthesized by postpolymerization fanctionalization of poly(3-(6-bromohexyl)-4'-dodecyl-2,2'-bithiophene) (12). 3-(6-Bromohexyl)-4'-dodecyl-2,2'-bithiophene (10), a key intermediate in the synthesis of polymer 12, was synthesized via Stille coupling of 2-bromo-3-(bromohexy)thiophene (8) and 2-trimethylstannyl-4-dodecylthiophene (9) in 30% isolated yield. Microstructure patterns of poly(3-(6-thiohexyl)-4'-dodecyl-2,2'-bithiophene) (1) were fabricated on a gold-coated glass slide through microcontact printing and microtransfer molding techniques. Circuit patterns of poly(3-hexylthiophene)s were constructed from a patterned silicon wafer via capillary force lithography methodology.