Facile Functionalization of Poly(3-alkylthiophene)s via Electrophilic Substitution

[Extract] Poly(thiophene)s have become the subject of extensive study. These materials are viewed as potentially useful components in field-effect transistors, optical and electronic sensors, light-emitting devices, nonlinear optical materials, etc. Substitution at the 3- and/or 4-position of the thiophene ring not only confers processability to poly(thiophene)s but can also be used to modify their electrooptical properties through electronic and steric interactions. However, it is difficult to prepare poly-(thiophene)s with a comprehensive list of functional groups due to either an intolerance of the functional group to the rather harsh polymerization conditions, the inhibition of monomer polymerization by the functional group, or the tedious nature of the synthetic procedures.