Neue Synthesestrategie zu a- und a,w-substituierten Oligo- und Polythiophenen und deren Selbstorganisation

Abstract

A new synthetic approach for long endcapped oligothiophenes without ß-substituents is presented. With this approach it is possible to prepare endcapped oligomers up to eleven thiophene rings. The use of a soluble precursor preserves the good solubility of the intermediate products in the course of the multi-step synthesis and gives rise to good yields and high purity compounds. Hence, the intermediates can be characterized by NMR, UV and MS spectroscopy before the ring closing reaction to the corresponding poorly soluble final oligothiophene takes place. The syntheses of the full series (1T to 7T or 11T, respectively) of a- and a,w-substituted oligothiophenes with linear and/or branched C20-alkyl chains are presented. Characterization of the oligomers by UV/Vis and fluorescence spectroscopy reveals strong aggregation phenomena of the longer compounds in solution depending on time, temperature and solvent.