Semiconducting Copolymeric Polythiophene Films*

Polymer matrices have now been built to involve site specific receptors. These receptor sites have been called templates and can be used for molecular recognition.1,2,3 In some ways the templated site in the polymer cavity is analogous to an enzymatic site.' Such templated polymer systems show promise of enhancing selectivity in chromatographic separations of organic molecules. It is also known that certain aromatic-like compounds, such as pyrrole, pyridine, and thiophene undergo anodic polymerizations which can be given semiconducting properties under controlled oxidizing conditions.' The electrical conductivities of these polymers can be changed by either altering the counterion or changing its concentration as the »dopant.. We will describe the preliminary experiments which show that semiconducting copolymers can be prepared in the polythiophene series and that these copolymers have binding sites suitable for surface binding studies or templating. The copolymer system chosen in this study is thiophene/thiophenenyl boronic acid. The dopant used is fluoride ion, obtained from lithium tetrafluoroborate. The system is shown below in Figure 1.